Fix JIT selection on Android with ARM builds

Debug builds on Android are done as ARM builds instead of thumb because of
problems with debugging thumb builds with older toolchains. However for the JIT
we're not interested in such a choice and prefer to have a consistent choice of
JIT - thumb2 generated code in release _and_ debug builds.

Change-Id: I36b1ec76311b409e36e3fb38c46c6c193adb1be8
Reviewed-by: Lars Knoll <lars.knoll@digia.com>