Update Launcher3 TAPL "find app icon" logic to allow whitespace.

Previously this used the content description which was generally the
same as the displayed text with whitespace adjustments + additional
text (e.g. "Play Store has 7 notifications").

That worked fine, but I thought it would be a bit more robust to work
with the text directly. Specifically, we consider it a match if all
of the non-whitespace characters are there, along with optional added
whitespace between characters. See TaplUtilityTests for examples.

More importantly for the other change in this topic, this Pattern is
also used for search result icons, to allow those tests to pass with
multiline labels enabled.

Bug: 315053839
Flag: LEGACY ENABLE_TWOLINE_DEVICESEARCH ENABLED
Test: Manual and TaplTestsTaskbarSearch + other unit tests

Change-Id: I4ad52840d743f06576d415f4e5ea6d8870e5dd2c