Refactored some resources, centralised Firebase topics by creating an emun 'Topic'

app/build.gradle

@@ -10,8 +10,8 @@ android {
         applicationId "com.denizd.substitutionplan"
         minSdkVersion 21
         targetSdkVersion 28
-        versionCode 36
-        versionName "2.2.13"
+        versionCode 37
+        versionName "2.2.14"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
     }
     buildTypes {
@@ -32,7 +32,7 @@ dependencies {
     implementation 'com.google.android.material:material:1.1.0-alpha10'
     implementation 'com.android.support:customtabs:28.0.0'
 
-    implementation 'com.google.firebase:firebase-core:17.1.0'
+    implementation 'com.google.firebase:firebase-core:17.2.0'
     implementation 'com.google.firebase:firebase-messaging:20.0.0'
     implementation 'com.crashlytics.sdk.android:crashlytics:2.10.1'