Update Biometric Prompt background cancel talkback string

Changes Biometric Prompt background to "Cancel" to match cancel button.
Also updates cancel button to match cancel button talkback action to
match background action of "Double tap to Cancel Authentication"

Test: atest AuthContainerViewTest
Bug: 353631541
Flag: EXEMPT bugfix
Change-Id: I6be1d718cafa3fe1abd376db5de0f04c3f357919