ModuleLicenseProviderTest converted to JUnit

The superclass ContentProvider's "getContext" method is final and
cannot be mocked, so a helper method visible for testing was added
to allow for context injection.

Bug: 175389659
Test: atest -c ModuleLicenseProviderTest
Change-Id: I9e20171340ae0a48d74fae44c7b356ea67dba43b

src/com/android/settings/deviceinfo/legal/ModuleLicenseProvider.java

@@ -62,7 +62,7 @@ public class ModuleLicenseProvider extends ContentProvider {
 
     @Override
     public String getType(Uri uri) {
-        checkUri(getContext(), uri);
+        checkUri(getModuleContext(), uri);
         return LICENSE_FILE_MIME_TYPE;
     }
 
@@ -83,7 +83,7 @@ public class ModuleLicenseProvider extends ContentProvider {
 
     @Override
     public ParcelFileDescriptor openFile(Uri uri, String mode) {
-        final Context context = getContext();
+        final Context context = getModuleContext();
         checkUri(context, uri);
         Preconditions.checkArgument("r".equals(mode), "Read is the only supported mode");
 
@@ -191,4 +191,10 @@ public class ModuleLicenseProvider extends ContentProvider {
     private static SharedPreferences getPrefs(Context context) {
         return context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE);
     }
+
+    // Method to allow context injection for testing purposes.
+    @VisibleForTesting
+    protected Context getModuleContext() {
+        return getContext();
+    }
 }