Add msim stubs to satisfy com.qualcomm.location linkage

Change-Id: Ie5bd60e668160d2fcfb75e634114a6115ca0c19f
Add a safe check to ensure start index is not negative

Change-Id: I9a6ffcf37882df9bd322296d6ea008b358ec2906
DocumentsUI: fix recursive delete

Create one DirectoryLoader in UI thread to use for delete

Change-Id: I83a5811f152090f7812ad58ff4ee3bc13748d158