Moving alarm manager native code to apex

Extracting out alarm manager jni from libandroid_servers to its own
library.

Test: lunch coral-userdebug && make -j
lunch bertha_arm-userdebug && make -j
atest CtsAlarmManagerTestCases

Bug: 151976605
Change-Id: Ie9e15b2665a2c51c9b2413af304e228f8a3ae2fc