Remove FLAG_SHOW_FOR_ALL_USERS to avoid crash

Temporarily removing flag to avoid crash in bug linked while we figure
out a solution for this. More details on bug linked.

Test: 1. Settings > Security > Enable Screen pinning.
      2. From overview > Tap on any app info > Select screen pinning
         > Tap on home bar and observe logcat
      3. Verify no crash
Bug: 149408635
Change-Id: Ieba081eae3f0cd66f99c54a2deb4e9653ec4cd9d