Use Trunk Stable Flags Only

Historically ASM used mendel flags. Now that trunbk stable flags are the default and only supported flagging mechanism, switch to only use these flags.

Bug: 416033243
Flag: android.security.asm_restrictions_v2
Test: atest ActivitySecurityModelTest (TODO)
Change-Id: I6e1db738cdbb1aee2027ea6e3496ea2846bdbd4d