Properly handle non-root tree-uri's
Summary
When sharing a non-root document tree (eg a folder beneath "Internal Storage" or "SD Card) the document Uri looks slightly different. This patch fixes that.
Test Plan
Before applying this patch configure only a non top storage location share (eg a directory on "Internal Storage") that has some files in it. Try to open one of the files using Dolphin should result in a "file not found" message
Apply patch and try to open the same file again. The file should now open as expected.