Refactor how location providers are managed

Put enabled/disabled state under location provider control, and use it
to represent whether a location provider may be used, not whether the
user has enabled or disabled a location provider.

Bug: 118885128
Test: manually
Change-Id: I1209c49c13ca8995b223f383ad332322fffc7a96
diff --git a/Android.bp b/Android.bp
index 5568673..d64e7a2 100644
--- a/Android.bp
+++ b/Android.bp
@@ -451,6 +451,7 @@
         "location/java/android/location/IGpsGeofenceHardware.aidl",
         "location/java/android/location/INetInitiatedListener.aidl",
         "location/java/com/android/internal/location/ILocationProvider.aidl",
+        "location/java/com/android/internal/location/ILocationProviderManager.aidl",
         "media/java/android/media/IAudioFocusDispatcher.aidl",
         "media/java/android/media/IAudioRoutesObserver.aidl",
         "media/java/android/media/IAudioService.aidl",