Consolidate Responsible API OWNERS

Introduces a new file that defines the owners for BAL logic.

Use this file for background activity start related files:
- BackgroundActivityStartController
- BackgroundActivityStartCallback
- BackgroundStartPrivileges
- BackgroundStartPrivilegesTest (in tests)

Change-Id: I3315a0f2216ed22a28b952f30afe0c3d14cfc955
Test: owners change only

BAL_OWNERS

+brufino@google.com
+achim@google.com
+topjohnwu@google.com
+lus@google.com
+

core/tests/coretests/src/android/app/OWNERS

@@ -10,3 +10,7 @@ per-file *UiAutomation* = file:/services/accessibility/OWNERS
 
 # KeyguardManagerTest
 per-file KeyguardManagerTest.java = file:/services/core/java/com/android/server/locksettings/OWNERS
+
+# Files related to background activity launches
+per-file Background*Start* = file:/BAL_OWNERS
+

services/core/java/com/android/server/wm/OWNERS

@@ -18,5 +18,8 @@ rgl@google.com
 yunfanc@google.com
 wilsonshih@google.com
 
-per-file BackgroundActivityStartController.java = set noparent
-per-file BackgroundActivityStartController.java = brufino@google.com, topjohnwu@google.com, achim@google.com, ogunwale@google.com, louischang@google.com, lus@google.com
+# Files related to background activity launches
+per-file Background*Start* = set noparent
+per-file Background*Start* = file:/BAL_OWNERS
+per-file Background*Start* = ogunwale@google.com, louischang@google.com
+