Add equals() for Resources.Theme

Bug: 155881035
Test: added a test case in cts
Change-Id: Icd0b3f4112f95ab2fc6ddfbd1b6ed7b2e85f1a3b

core/java/android/content/res/Resources.java

@@ -1923,6 +1923,25 @@ public class Resources {
                 }
             }
         }
+
+        @Override
+        public int hashCode() {
+            return getKey().hashCode();
+        }
+
+        @Override
+        public boolean equals(@Nullable Object o) {
+            if (this == o) {
+                return true;
+            }
+
+            if (o == null || getClass() != o.getClass() || hashCode() != o.hashCode()) {
+                return false;
+            }
+
+            final Theme other = (Theme) o;
+            return getKey().equals(other.getKey());
+        }
     }
 
     static class ThemeKey implements Cloneable {