Refactor the Jetpack test utils

Refactor the Jetpack test utils so that we can reuse it to get the
info from the WindowManager Jetpack library for the EDI.

Bug: 168732027
Test: atest CtsWindowManagerJetpackTestCases:ExtensionTest
Change-Id: I0b0f1c0b1b6b79e467fd9e4c094b4ed86ea6a993
17 files changed