adding Lab7 Firebase

labs/Lab7_Firebase/.gitignore

labs/Lab7_Firebase/.idea/.name

labs/Lab7_Firebase/.idea/codeStyles/Project.xml

labs/Lab7_Firebase/.idea/codeStyles/codeStyleConfig.xml

labs/Lab7_Firebase/.idea/gradle.xml

labs/Lab7_Firebase/.idea/jarRepositories.xml

labs/Lab7_Firebase/.idea/misc.xml

labs/Lab7_Firebase/.idea/runConfigurations.xml

labs/Lab7_Firebase/.idea/vcs.xml

labs/Lab7_Firebase/Lab7_Firebase.pdf

labs/Lab7_Firebase/Lab7_walkthrough.mp4

labs/Lab7_Firebase/app/.gitignore

labs/Lab7_Firebase/app/build.gradle

labs/Lab7_Firebase/app/google-services.json

labs/Lab7_Firebase/app/proguard-rules.pro

...roidTest/java/com/example/lab7_firebase/TestValidation.kt

labs/Lab7_Firebase/app/src/main/AndroidManifest.xml

...ase/app/src/main/java/com/example/lab7_firebase/Author.kt

...src/main/java/com/example/lab7_firebase/AuthorActivity.kt

...app/src/main/java/com/example/lab7_firebase/AuthorList.kt