Remove enabled flag fix_merged_content_change_event_v2

It has been enabled 6 month.

Bug: 277305460
Test: atest AccessibilityEventAndCacheTest
Flag: EXEMPT removing com.android.server.accessibility.fix_merged_content_change_event_v2
Change-Id: I12b05bddcec3ec157998f0efc589a4e3fa2a3318
1 file changed