galaxys2: Use default message and image sizes for Mms

While the phone can handle 600k Mms messages, and images in Mms of
1600x1200... most networks won't allow this. Remove these overlay
settings to revert back to default sizes (300k, 640x480) to ensure
that messages will send on all networks.

Change-Id: I7a852c2121dd72e4a7788dc09a70febe1e95e005