AOSP/UnifiedEmail - Secure UPDATE_WIDGET receiver with a new permission

The update methods sends a broadcast with the account name, the folder, etc.
This implicitly bypasses the GET_ACCOUNT permission if a third-party
applications listens to this broadcast.

- Introduce a new app permission
- Now the is required to
- receive the emitted broadcast
- Add this permission to our existing widgets.

Ported changes from cr/106302205
- added uses-permission GET_WIDGET_UPDATE, so Gmail app has the permission to receive the intent

Bug: 139803872

Test: manual - Ran the following tests on Pixel phone. Tested the email UI.

$ make -j 40
$ make Email -j
$ make EmailTests -j
  -rw-r--r-- 1 rtenneti primarygroup 6356400 Sep 16 14:10 out/target/product/marlin/testcases/Email/arm64/Email.apk
  -rw-r--r-- 1 rtenneti primarygroup 389599 Sep 16 14:18 out/target/product/marlin/testcases/EmailTests/arm64/EmailTests.apk

$ adb install -r -d -g out/target/product/marlin/testcases/Email/arm64/Email.apk
$ adb install -r -d -g out/target/product/marlin/testcases/EmailTests/arm64/EmailTests.apk
$ adb shell am instrument -w
  Time: 34.746
  OK (157 tests)

$ atest EmailTests
  EmailTests: Passed: 157, Failed: 0, Ignored: 0, Assumption Failed: 0

  All tests passed!

$ adb install ../security_attack/bug_139803872/poc.apk
  Captured the logcat output at rtenneti's x20web logcat.out.0916.1503
  while reproducting the steps in b/139803872#comment3

Change-Id: Ied292eab76c672c60de57f8ce43df0e0ea6d3464
Merged-In: Ied292eab76c672c60de57f8ce43df0e0ea6d3464
2 files changed