Add dependency change warning to copilot-instructions.md, Fixes AB#3557152 (#3045)

When any change is made to a build.gradle or versions.gradle file that
adds a new dependency or changes a dependency version, Copilot will now
display a warning pointing to the Adding or Updating Gradle Dependencies
documentation.


[AB#3557152](https://identitydivision.visualstudio.com/fac9d424-53d2-45c0-91b5-ef6ba7a6bf26/_workitems/edit/3557152)

---------

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: p3dr0rv

.github/copilot-instructions.md

@@ -554,6 +554,11 @@ See [changelog.txt](../changelog.txt) for the changelog format.
 
 ## 11. Dependencies & Versioning
 
+When any change is made to a `common/build.gradle` file or the shared dependency versions file at `gradle/versions.gradle` that adds a new dependency or changes a dependency version, always display the following warning message:
+> ⚠️ **Warning:** Changes detected ⚠️
+>
+> Please follow the recommendations in [Adding or Updating Gradle Dependencies](https://eng.ms/docs/microsoft-security/identity/entra-developer-application-platform/auth-client/authn-sdk-msal-android/android-auth-libraries/how-tos/adding-or-updating-gradle-dependencies).
+
 Flag:
 - Security library downgrade.
 - Major upgrade without referenced release notes.
@@ -674,4 +679,4 @@ Always cite specific code and give a minimal, actionable fix; use an assumption
 
 ---
 
-Thank you for contributing to this project!
+Thank you for contributing to this project!