Flag cleanup: Remove AAPM MTE flag

Clean up the android.security.aapm_feature_memory_tagging_extension,
as it has been launched.

Bug: 423961722
Test: atest CtsSecurityTestCases:android.security.cts.advancedprotection.MemoryTaggingExtensionTest
Flag: EXEMPT removing android.security.aapm_feature_memory_tagging_extension

Change-Id: Ieb3424d95ebb32033d07d2d036e906227e01f29f