Revert^2 "[PM] Add invisible label detection in Launcher apps"

Revert submission 25370324-revert-25320514-light_label_detection_launcher-PDWTKFXLDD

Reason for revert: Reland with
                   1. Remove Character#toString(int codePoint)
		   2. Add new aconfig to guard it

Reverted changes: /q/submissionid:25370324-revert-25320514-light_label_detection_launcher-PDWTKFXLDD

Test: atest LauncherActivityInfoTest
Test: atest CtsPackageManagerTestCases:LauncherAppsTest
Bug: 299586370
Bug: 309896458
Bug: 307309770
Change-Id: I001c8db38801320928429e78d7d68a1e437ea066