Revert "update SystemUI's proguard.flags"

Revert this since there are reports of breaking in the comments on cm gerrit.

This reverts commit c7add6a6eeacd6dc86e242967f8740ea47487ca2.
Revert "Allow multiple emulated storages at the same time."

Reverted because of same reason as last commit.
This reverts commit 1cffc7e542e8e792df04b32000038abf466deb8f.