TARE string clarification

Clarify the strings used for the TARE homepage. Update
comments so that the translators understand that TARE is not
translatable and that AlarmManager and JobScheduler are Android system
services.

Bug: 191876567

Test: Manual (open Settings > System > Developer Options > TARE and
verify tabs and menus are there)

Change-Id: I935cd0ab9e8e6e5591875a1e7f8ed9f58d8abd9c