Fix FGS mode in test

Corrects testBoundByForegroundFgs to use mFgsCheckConfiguration, aligning the test with its intended purpose of testing Foreground Service (FGS) scenarios.

Removes the obsolete testBoundByForegroundOld test method (as thethe BAL codes changed to BLOCKED for this case)

Flag: EXEMPT CVE_FIX
Test: atest BackgroundActivityLaunchProcessorTest
Bug: 508112183
Bug: 464526458
Cherrypick-From: https://googleplex-android-review.googlesource.com/q/commit:e26dda735b99edd974444462ce5b333dbbd3aa6a
Merged-In: Iab1fe3b66e73e057d4410dff93a44c13be5bfc76
Change-Id: Iab1fe3b66e73e057d4410dff93a44c13be5bfc76