Retire `ro.kernel.android.checkjni` from AndroidRuntime.cpp

this property is deprecated and emulator now
populates `dalvik.vm.checkjni` to use instead.

Bug: 182291166
Test: getprop dalvik.vm.checkjni
Signed-off-by: Roman Kiryanov <rkir@google.com>
Change-Id: Ie94b0d6c2e48b731d9cfe0ead380e0f52f662f37