chore: Explicitly include specific group of libraries for README's BOM section generation (#4028)

Group ids included in the gapic-libraries-bom are 

- com.google.cloud
- com.google.analytics
- com.google.area120

This inclusion list is specified [in the
generator](https://github.com/googleapis/sdk-platform-java/blob/32d8aa1ce0a19fb45c1af226d59786d803f4c6c8/hermetic_build/library_generation/utils/pom_generator.py#L86-L90).
Use the same list for README's BOM section generation.

Verified in [google-cloud-java
](https://github.com/googleapis/google-cloud-java/pull/11852/files)
using SNAPSHOT version of generator that groups ids (e.g. ads) outside
of these three are correctly excluded.

Author: blakeli0

hermetic_build/library_generation/owlbot/templates/java_library/README.md

@@ -36,7 +36,7 @@ If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file:
 ```
 
 If you are using Maven without the BOM, add this to your dependencies:
-{% elif monorepo %}
+{% elif monorepo and (group_id == "com.google.cloud" or group_id == "com.google.analytics" or group_id == "com.google.area120") %}
 If you are using Maven with [BOM][libraries-bom], add this to your pom.xml file:
 
 ```xml