chore(deps): bump agp from 9.1.0 to 9.2.1 in /android-tests

Bumps `agp` from 9.1.0 to 9.2.1.

Updates `com.android.tools.build:gradle-api` from 9.1.0 to 9.2.1

Updates `com.android.library` from 9.1.0 to 9.2.1

---
updated-dependencies:
- dependency-name: com.android.tools.build:gradle-api
  dependency-version: 9.2.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
- dependency-name: com.android.library
  dependency-version: 9.2.1
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

android-tests/gradle/libs.versions.toml

@@ -1,5 +1,5 @@
 [versions]
-agp = "9.1.0"
+agp = "9.2.1"
 junitJupiterApi = "5.14.3"
 kotlin = "2.3.20"
 endive = "999-SNAPSHOT"