Log a warning if content view exceeds char limit

1. Remove the exception for content view char limit and log a warning
   instead
2. Truncate and ellipsize if it exceeds the char limit

Flag: android.hardware.biometrics.custom_biometric_prompt
Test: atest PromptContentViewScreenshotTest
Bug: 359957211
(cherry picked from commit 8d84f1d4)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:a487f90fe3c367fb52fddc557e4aff5407262145)
Merged-In: I76921d118f9510457a8cb953a350259bd42eb17c
Change-Id: I76921d118f9510457a8cb953a350259bd42eb17c