Disable KEYGUARD_TALKBACK_FIX flag

Upon review, the fix was against a11y policies
rather than in compliance with.

Flag: LEGACY KEYGUARD_TALKBACK_FIX DISABLED
Fixes: 330429983
Test: enable talback and observe not all the messages
on the lockscreen keyguard bottom area are announced

Change-Id: I1556c8456342ef55ce75d72de20a6502bba253f6