Fix launcher selector

When a notification appears, the content-desc of the launcher icon also
contains information about the notifications the app has. Switiching to
the text field gets around this issue.

Bug: 73256630
Bug: 73255749
Bug: 72864871

Test: VZ DoU gmail tests with and without pending notifications
Change-Id: I6f380cab612e871e0c9617a341fb701903eae725