Add the flag "disable-content-trust " as a NOOP

[delvin1933]

Is this a BUG REPORT or FEATURE REQUEST? (leave only one on its own line)

/kind feature

Description

Add the flag "disable-content-trust " as a NOOP, it is already implemented in buildah
I am working with the serverless framework to develop serverless application with podman as my container implementation.

I use podman-docker.

The serverless framework calls docker with the "--disable-content-trust=false" flag, causing a local invocation to fail when downloading the base docker image.

Steps to reproduce the issue:
Following https://github.com/softprops/serverless-aws-rust

1. npx serverless install
   --url https://github.com/softprops/serverless-aws-rust
   --name my-new-app

2. cd my-new-app

3. npm ci

4. npx serverless invoke local -f hello -d '{"foo":"bar"}'

Describe the results you received:

the invocation fails with the following message

Serverless: Downloading base Docker image...
 
  Error --------------------------------------------------
 
  Error: `docker pull --disable-content-trust=false lambci/lambda:provided` Exited with code 125
      at ChildProcess.spawn.on (/home/cfarges/aventure/rust-lambda2/tmp/my-new-app/node_modules/child-process-ext/spawn.js:38:8)
      at ChildProcess.emit (events.js:189:13)
      at ChildProcess.EventEmitter.emit (domain.js:441:20)
      at maybeClose (internal/child_process.js:970:16)
      at Process.ChildProcess._handle.onexit (internal/child_process.js:259:5)
 
     For debugging logs, run again after setting the "SLS_DEBUG=*" environment variable.
 
  Get Support --------------------------------------------
     Docs:          docs.serverless.com
     Bugs:          github.com/serverless/serverless/issues
     Issues:        forum.serverless.com
 
  Your Environment Information ---------------------------
     Operating System:          linux
     Node Version:              10.15.1
     Framework Version:         1.74.1
     Plugin Version:            3.6.15
     SDK Version:               2.3.1
     Components Version:        2.31.10

Describe the results you expected:

a successful invocation

Additional information you deem important (e.g. issue happens only occasionally):

Output of podman version:

% podman version                                                 
Version:      2.0.2
API Version:  1
Go Version:   go1.14.3
Built:        Thu Jan  1 01:00:00 1970
OS/Arch:      linux/amd64

Output of podman info --debug:

host:
  arch: amd64
  buildahVersion: 1.15.0
  cgroupVersion: v2
  conmon:
    package: conmon-2.0.18-1.fc32.x86_64
    path: /usr/libexec/crio/conmon
    version: 'conmon version 2.0.18, commit: 6e8799f576f11f902cd8a8d8b45b2b2caf636a85'
  cpus: 12
  distribution:
    distribution: fedora
    version: "32"
  eventLogger: file
  hostname: lgop2497
  idMappings:
    gidmap:
    - container_id: 0
      host_id: 1000
      size: 1
    - container_id: 1
      host_id: 100000
      size: 65536
    uidmap:
    - container_id: 0
      host_id: 1000
      size: 1
    - container_id: 1
      host_id: 100000
      size: 65536
  kernel: 5.7.8-200.fc32.x86_64
  linkmode: dynamic
  memFree: 569004032
  memTotal: 33417416704
  ociRuntime:
    name: crun
    package: crun-0.14.1-1.fc32.x86_64
    path: /usr/bin/crun
    version: |-
      crun version 0.14.1
      commit: 598ea5e192ca12d4f6378217d3ab1415efeddefa
      spec: 1.0.0
      +SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +YAJL
  os: linux
  remoteSocket:
    path: /run/user/1000/podman/podman.sock
  rootless: true
  slirp4netns:
    executable: /usr/bin/slirp4netns
    package: slirp4netns-1.1.1-1.fc32.x86_64
    version: |-
      slirp4netns version 1.1.1
      commit: bbf27c5acd4356edb97fa639b4e15e0cd56a39d5
      libslirp: 4.2.0
      SLIRP_CONFIG_VERSION_MAX: 2
  swapFree: 16768069632
  swapTotal: 16804474880
  uptime: 163h 45m 28.74s (Approximately 6.79 days)
registries:
  search:
  - registry.fedoraproject.org
  - registry.access.redhat.com
  - registry.centos.org
  - docker.io
store:
  configFile: /home/cfarges/.config/containers/storage.conf
  containerStore:
    number: 0
    paused: 0
    running: 0
    stopped: 0
  graphDriverName: overlay
  graphOptions:
    overlay.mount_program:
      Executable: /usr/bin/fuse-overlayfs
      Package: fuse-overlayfs-1.1.2-1.fc32.x86_64
      Version: |-
        fusermount3 version: 3.9.1
        fuse-overlayfs: version 1.1.0
        FUSE library version 3.9.1
        using FUSE kernel interface version 7.31
  graphRoot: /home/cfarges/.local/share/containers/storage
  graphStatus:
    Backing Filesystem: btrfs
    Native Overlay Diff: "false"
    Supports d_type: "true"
    Using metacopy: "false"
  imageStore:
    number: 86
  runRoot: /run/user/1000
  volumePath: /home/cfarges/.local/share/containers/storage/volumes
version:
  APIVersion: 1
  Built: 0
  BuiltTime: Thu Jan  1 01:00:00 1970
  GitCommit: ""
  GoVersion: go1.14.3
  OsArch: linux/amd64
  Version: 2.0.2

Package info (e.g. output of rpm -q podman or apt list podman):

podman-2.0.2-1.fc32.x86_64

Additional environment details (AWS, VirtualBox, physical, etc.):

[mheon]

Fixed by #7036