Updating firebase-perf external documentation as part of Open Sourcing (#2359)

Author: ramanpreetSinghKhinda

README.md

@@ -22,6 +22,8 @@ dependencies:
   * `firebase-inappmessaging-ktx`
   * `firebase-inappmessaging-display`
   * `firebase-inappmessaging-display-ktx`
+  * `firebase-perf`
+  * `firebase-perf-ktx`
   * `firebase-remote-config`
   * `firebase-remote-config-ktx`
   * `firebase-storage`

docs/README.md

@@ -12,6 +12,7 @@ This repository includes the following Firebase SDKs for Android:
   * `firebase-firestore`
   * `firebase-functions`
   * `firebase-inappmessaging-display`
+  * `firebase-perf`
   * `firebase-storage`
 
 For more information on building the SDKs from source or contributing,