Move the `isRecording` state in Issuerecording service into a global

settings rather than a user-specific variable.

This is important for when IssueRecordingService and RecordIssueTile are
in different user profiles. Otherwise, we run into the issue of the tile
not being updated when the notification actions switch the tile state.

Bug: 364824477
Test: Verified locally that System Tracing via the Record Issue Tile
works great in Headless System User Mode.
Flag: EXEMPT bug fix

Change-Id: I4f502229caf48d933763e0b15c1502aa9618959c