Bump com.microsoft.graph:microsoft-graph-core in /android

Bumps [com.microsoft.graph:microsoft-graph-core](https://github.com/microsoftgraph/msgraph-sdk-java-core) from 2.0.20 to 2.0.21.
- [Release notes](https://github.com/microsoftgraph/msgraph-sdk-java-core/releases)
- [Changelog](https://github.com/microsoftgraph/msgraph-sdk-java-core/blob/dev/CHANGELOG.md)
- [Commits](microsoftgraph/msgraph-sdk-java-core@v2.0.20...v2.0.21)

---
updated-dependencies:
- dependency-name: com.microsoft.graph:microsoft-graph-core
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

gradle/dependencies.gradle

@@ -11,5 +11,5 @@ dependencies {
     implementation 'com.squareup.okhttp3:okhttp:4.12.0'
 
     // Core Http library 
-    api 'com.microsoft.graph:microsoft-graph-core:2.0.20'
+    api 'com.microsoft.graph:microsoft-graph-core:2.0.21'
 }