docs: update versions in install docs (#4063)

Lots of the versions were very old, I pinned them to current stable
The most important one is the google services plugin to 4.3.3 though, it has
lots of serious issues in the 4.2.0 version specified

docs/index.md

@@ -61,7 +61,7 @@ First, add the `google-services` plugin as a dependency inside of your `/android
 buildscript {
   dependencies {
     // ... other dependencies
-    classpath 'com.google.gms:google-services:4.2.0'
+    classpath 'com.google.gms:google-services:4.3.3'
     // Add me --- /\
   }
 }
@@ -186,15 +186,15 @@ project.ext {
       // Overriding Build/Android SDK Versions
       android : [
         minSdk    : 16,
-        targetSdk : 28,
-        compileSdk: 28,
-        buildTools: "28.0.3"
+        targetSdk : 29,
+        compileSdk: 29,
+        buildTools: "29.0.3"
       ],
 
       // Overriding Library SDK Versions
       firebase: [
         // Override Firebase SDK Version
-        bom           : "21.1.0"
+        bom           : "25.7.0"
       ],
     ],
   ])
@@ -209,7 +209,7 @@ Open your projects `/ios/Podfile` and add any of the globals shown below to the
 
 ```ruby
 # Override Firebase SDK Version
-$FirebaseSDKVersion = '6.13.0'
+$FirebaseSDKVersion = '6.29.0'
 ```
 
 Once changed, reinstall your projects pods via pod install and rebuild your project with `npx react-native run-ios`.