[SB][Screen Chips] Update dialog strings.

Updates include:
 - Share-to-app: Include which app is receiving the screen share if
   you're sharing your entire screen
 - Cast-screen-to-other-device: Include name of device receiving the
   cast
 - Removes bolding of the app name
 - Better fallback strings
 - Minor text changes

Bug: 332662551
Bug: 351851835
Flag: com.android.systemui.status_bar_screen_sharing_chips

Test: Share-to-app, share single app -> dialog includes name of app
being shared
Test: Share-to-app, entire screen -> dialog includes just name of app
receiving the share

Test: Cast only audio to other device -> dialog includes device name
Test: Cast screen to other device, single app -> dialog includes both
name of app being shared and device name
Test: Cast screen to other device, entire screen -> dialog includes
device name

Test: Screen recording -> minor text changes

Change-Id: Id9710270bafef03d5f0c4e1cece124df8fd59755