Add shell commands and dump information for Translation

1. Add shell command to allow a temporary override of the
TranslationService that helps e2e CTS tests.
2. Add permission to allow the shell call the UiTranslationManager
APIs for the tests.
3. Dump translation systemservice and activity translation related
information to help debugging

We don't want to leak translation feature now, so we submit the
change about Shell in internal branch.

Bug: 179047265
Test: manual.
1. Switch to temp TranslationService by "adb shell cmd transformer set
<myTranslationService> 12000" and make sure only the same app can
access the APIs when switching to the temp service.
2. adb shell dumpsys transformer
3. adb shell dumpsys activity <myactivity> --translation
(We set "transformer" now to prevent feature leak, the final value is
translation)

Change-Id: I2573b7ea226bd805a951f8346d5370d9c9776364