Read from aflags in dumpstate

Aconfig flag storage will be ramped imminently, so add a dump of the new storage
to bugreports. The dump will dump DeviceConfig if the new storage is disabled,
and the new storage if it's enabled.

Test: adb bugreport /tmp/bugreport.zip && unzip -c /tmp/bugreport.zip bugreport*.txt | grep 'ACONFIG FLAGS DUMP'
Test: adb bugreport /tmp/bugreport.zip && unzip -c /tmp/bugreport.zip bugreport*.txt | grep 'WHICH ACONFIG FLAG STORAGE'
Bug: 324436145
Change-Id: If89f62b003d2a7285e9e915d831b36ab84ca43c3