setTemporaryAppWhitelistDuration(long duration) is deprecated.

Call new API setTemporaryAppAllowlist() and specify temp-allowlist reasonCode.

Bug: 171305836
Test: atest cts/tests/app/src/android/app/cts/ActivityManagerFgsBgStartTest.java
Reboot device, observe "tempAllowListReason" in logcat.

Change-Id: I705b97e33a2b28d6f081b1c4679f27ad559ad4df
BYPASS_INCLUSIVE_LANGUAGE_REASON=Existing public API.