Time out sync reset if device is offline

[srirambv]

Description

Time out sync reset if device is offline

Steps to Reproduce

1. Create sync chain on desktop with another device
2. Disconnect device from network
3. Try to delete the device from sync chain, keeps showing the remove device modal, laptop engines start revving up at 3000 RPM and is ready to take off

Actual result:

Device never gets removed from sync chain if device is offline

Expected result:

Should time out and cancel request to remove after a short interval

Reproduces how often:

Easy

Brave version (brave://version info)

All

Reproducible on current release:

• Does it reproduce on brave-browser dev/beta builds?
  Yes

Website problems only:

• Does the issue resolve itself when disabling Brave Shields?
• Is the issue reproducible on the latest version of Chrome?

Additional Information

Bringing device back online, modal doesn't close (device is not removed)
cc: @darkdh @AlexeyBarabash

[srirambv]

Verification passed on

Brave	1.3.112 Chromium: 80.0.3987.87 (Official Build) (64-bit)
Revision	449cb163497b70dbf98d389f54e38e85d4c59b43-refs/branch-heads/3987@{#801}
OS	Windows 10 OS Version 1803 (Build 17134.165)

• Verified test plan from Fix 3628 offline reset brave-core#4089
• Verified device can be removed from sync chain when offline
• Verified no bookmarks are sent across even though the device is listed but removed from sync chain

Verification passed on

Brave	1.3.113 Chromium: 80.0.3987.87 (Official Build) (64-bit)
Revision	449cb163497b70dbf98d389f54e38e85d4c59b43-refs/branch-heads/3987@{#801}
OS	Ubuntu 18.04 LTS

• Verified test plan from Fix 3628 offline reset brave-core#4089
• Verified device can be removed from sync chain when offline
• Verified no bookmarks are sent across even though the device is listed but removed from sync chain