Fix a broken test by mocking PackageManager

There is no email app in AOSP, and thus the test fails.
Mocking the package manager output to fix the test

Test: atest frameworks/base/core/tests/coretests/src/android/view/textclassifier/TextClassifierTest.java

Fixes: 139536812
Fixes: 145209230
Fixes: 145287677

Change-Id: I86026724c81f9d928eb652f25fc968911f93001b
Merged-In: Ie2dd599528074266d45044b1785a1b7d71caa1d3

Exempt-From-Owner-Approval: Re-enabling test in TEST_MAPPING
for AOSP.