AppStandby exemption: sync requested by FG apps

Bug: 72443754
Fix: 72443754

Test: atest ${ANDROID_BUILD_TOP}/frameworks/base/services/tests/servicestests/src/com/android/server/content/SyncOperationTest.java
Test: Manual test with contacts sync:

Precondition: Put the contacts sync in RARE bucket.

adb shell dumpsys deviceidle tempwhitelist -r com.google.android.syncadapters.contacts
adb shell am make-uid-idle com.google.android.syncadapters.contacts
adb shell am set-standby-bucket com.google.android.syncadapters.contacts 40

Test 1: Toggle contacts sync from the Settings -> Account

- Make sure a sync happens.

Test 2: Mutate a contact on the WEB

- Sync is scheduled, but won't run because it has no network access.
- am set-standby-bucket com.google.android.syncadapters.contacts 30
- Sync run runs.

Test 3. adb shell requestsync -n ACCOUNT -t com.google -a com.android.contacts

- Sync is scheduled but won't run.

Test 4. adb shell requestsync -n ACCOUNT -t com.google -a com.android.contacts -f

- Sync is scheduled but it still won't run.

Test 5. adb shell requestsync -n ACCOUNT -t com.google -a com.android.contacts -F

- Sync now runs

Change-Id: I1eb972ed321d2a1a782ae23ccb806671926d3e6b