Revert "Removing workaround for battery defender"

This reverts commit f4bb052c.

Reason: we have new episodes of phone locking during the test.
https://flakes-clusters.corp.google.com/#?androidAtpBranch=git_sc-dev&androidAtpModule=com.google.android.apps.nexuslauncher.out_of_proc_tests&d=3&maxResults=10

https://flakes-clusters.corp.google.com/#?androidAtpBranch=git_sc-dev&androidAtpModule=com.google.android.apps.nexuslauncher.tests&d=3&maxResults=10

Search for "Phone is locked" and "Keyguard is visible".

Also, for new devices, the phone is locked consistently, see for example
Redfin here:
https://blackbox.googleplex.com/dashboard/Launcher3Main_new_devices/testsuite/git_master/nexuslauncher_oop_tests_platform/2/bramble-userdebug/0

Reverting to see whether this helps.

Bug: 151613234
Test: presubmit
Change-Id: I44a94f9722deaa21d89fdfd79646ae661ebe972d