Disable memory trimming on AoD and on unlock

This disables font cache trimming on transition to AoD and when
unlocking the device - it's suspected to cause a large amount of jank.

The memory increases from fonts have been mitigated with other CLs, particularly I3f342fd7d427b8b6cfcd2e83480fbbb36d6782ea and I99dd4108eef34156c4f8f79bbb042703325ed82d . This CL doesn't seem to contribute much and is a strong suspect for adding a lot of jank.

Bug: 275486055
Bug: 286779126
Bug: 290277152
Test: ran perf test http://ab/I09600010175683794

(cherry picked from commit 064a05f3)
(cherry picked from https://googleplex-android-review.googlesource.com/q/commit:a33246b5c7b16475952755901e64de37a4ef52d9)
Merged-In: Iaf1735e605ee54845cd3943f8cac6a62c37a5877
Change-Id: Iaf1735e605ee54845cd3943f8cac6a62c37a5877