Move all integration tests to separate tests folder.

PiperOrigin-RevId: 293402855

Author: wu-hui

firestore/src/android/firestore_android_test_main.cc renamed to firestore/src/tests/android/firestore_android_test_main.cc

@@ -1,7 +1,7 @@
-#ifndef FIREBASE_FIRESTORE_CLIENT_CPP_SRC_COMMON_EVENT_ACCUMULATOR_H_
-#define FIREBASE_FIRESTORE_CLIENT_CPP_SRC_COMMON_EVENT_ACCUMULATOR_H_
+#ifndef FIREBASE_FIRESTORE_CLIENT_CPP_SRC_TESTS_UTIL_EVENT_ACCUMULATOR_H_
+#define FIREBASE_FIRESTORE_CLIENT_CPP_SRC_TESTS_UTIL_EVENT_ACCUMULATOR_H_
 
-#include "firestore/src/common/firestore_integration_test.h"
+#include "firestore/src/tests/firestore_integration_test.h"
 
 namespace firebase {
 namespace firestore {
@@ -86,4 +86,4 @@ class EventAccumulator {
 
 }  // namespace firestore
 }  // namespace firebase
-#endif  // FIREBASE_FIRESTORE_CLIENT_CPP_SRC_COMMON_EVENT_ACCUMULATOR_H_
+#endif  // FIREBASE_FIRESTORE_CLIENT_CPP_SRC_TESTS_UTIL_EVENT_ACCUMULATOR_H_