Update RecipeVersionWriter.java (#5382)

Update the AGP version.

Author: rlazo

buildSrc/src/main/java/com/google/firebase/gradle/bomgenerator/RecipeVersionWriter.java

@@ -44,7 +44,7 @@ public String generateVersionUpdate() {
             "com.google.gms:google-services"));
     outputBuilder.append(
         "  <!ENTITY google-services-plugin \"com.google.gms.google-services\">\n"
-            + "  <!ENTITY gradle-plugin-class \"com.android.tools.build:gradle:3.4.0\">\n");
+            + "  <!ENTITY gradle-plugin-class \"com.android.tools.build:gradle:7.3.0\">\n");
     outputBuilder.append("\n");
     outputBuilder.append("  <!-- Firebase SDK libraries -->\n");
     outputBuilder.append(