skip android in @skipIfHostIncompatibleWithRemote

The current implementation of the decorator does not skip if the android target
arch is the same as host arch (as in both cases the platform comes out as linux).
Nonetheless android x86_64 binaries are not compatible with linux ones.

Technically this should be "skip if target is android and host is *not* android",
but currently nobody runs lldb test suite on an android host, so we don't even
have a way of specifying that the host is android.

llvm-svn: 288027