Remove sepolicy module from system image.

Attempt #2. Previous attempt didn't remove precompiled sepolicy from
system image, which lead to 1s boot time regression. This is not being removed in the topic.

Include merged-in tag, to skip git_master revert.

Bug: 199914227
Test: presubmit and manual verification
Merged-In: Iafe242c8c7122174788215a02e03c8903316a223
Change-Id: Idea61f53411c541b06d74883711d633b822316d6