Revert "use a solid black not a gradient as background"

This reverts commit 859f79e9e0ff9c6c45841846d2afe5f3a21eefd8.
Revert "ResolverActivity: don't use Holo Light"

This reverts commit 756b6d3cc48beb4a9a7e9a7d0b1c451d93d13d26.