fix(database): database emulator config respects android_bypass_emula…

…tor_url_remap flag

this was an oversight in previous versions, the firebase.json flag to ignore
the built-in android localhost -> 10.0.2.2 remapping for transparently-working
emulator out of the box for the general case was ignored

packages/database/lib/index.js

@@ -188,12 +188,22 @@ class FirebaseDatabaseModule extends FirebaseModule {
       throw new Error('firebase.database().useEmulator() takes a non-empty host and port');
     }
     let _host = host;
-    if (isAndroid && _host) {
-      if (_host === 'localhost' || _host === '127.0.0.1') {
-        _host = '10.0.2.2';
+    const androidBypassEmulatorUrlRemap =
+      typeof this.firebaseJson.android_bypass_emulator_url_remap === 'boolean' &&
+      this.firebaseJson.android_bypass_emulator_url_remap;
+    if (!androidBypassEmulatorUrlRemap && isAndroid && _host) {
+      if (_host.startsWith('localhost')) {
+        _host = _host.replace('localhost', '10.0.2.2');
         // eslint-disable-next-line no-console
         console.log(
-          'Mapping database host to "10.0.2.2" for android emulators. Use real IP on real devices.',
+          'Mapping database host "localhost" to "10.0.2.2" for android emulators. Use real IP on real devices. You can bypass this behaviour with "android_bypass_emulator_url_remap" flag.',
+        );
+      }
+      if (_host.startsWith('127.0.0.1')) {
+        _host = _host.replace('127.0.0.1', '10.0.2.2');
+        // eslint-disable-next-line no-console
+        console.log(
+          'Mapping database host "127.0.0.1" to "10.0.2.2" for android emulators. Use real IP on real devices. You can bypass this behaviour with "android_bypass_emulator_url_remap" flag.',
         );
       }
     }