Merge remote-tracking branch 'origin/master' into Version-v7.3.0

* origin/master:
  Add v7.2.2 to changelog
  Update minimum Firefox verison to 56.0 (#7213)
  Version v7.2.2
  Update changelog for v7.2.1, v7.2.0, and v7.1.1
  Add `appName` message to each locale
  Version v7.2.1
  Update changelog with additional bug fixes
  Fix recipient field of approve screen (#7171)
  Replace `undefined` selectedAddress with `null` (#7161)
  Add polyfill for AbortController (#7157)
  Set minimum Firefox version to v56.2 to support Waterfox (#7156)
  Publish GitHub release from master branch (#7136)
  Update the changelog for v7.1.1 (#7145)
  build - replace gulp-uglify-es with gulp-terser-js
  Version v7.2.0
  Update changelog with 7.2.0 changes
  Allow dismissing privacy mode from popup
  Add changelog
  Version v7.1.1