Handle unknown case in LocationManager.getProvider

If a provider is unknown, return null in
LocationManagerService.getProviderProperties() instead of throwing a
security exception, so that LocationManager.getProvider() returns null
in this case, as specified by the javadoc.

Bug: 7359960
Change-Id: I1b8b74745f66717a3439a1d353a46a23272cc313

Author: laurenttu

services/java/com/android/server/LocationManagerService.java

@@ -1340,6 +1340,10 @@ public boolean sendNiResponse(int notifId, int userResponse) {
      */
     @Override
     public ProviderProperties getProviderProperties(String provider) {
+        if (mProvidersByName.get(provider) == null) {
+          return null;
+        }
+
         checkPermissionForProvider(getBestCallingPermission(), provider);
 
         LocationProviderInterface p;