Bump robolectric from 4.8.1 to 4.9

Bumps [robolectric](https://github.com/robolectric/robolectric) from 4.8.1 to 4.9.
- [Release notes](https://github.com/robolectric/robolectric/releases)
- [Commits](robolectric/robolectric@robolectric-4.8.1...robolectric-4.9)

---
updated-dependencies:
- dependency-name: org.robolectric:robolectric
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

owncloudComLibrary/build.gradle

@@ -16,7 +16,7 @@ dependencies {
     kapt "com.squareup.moshi:moshi-kotlin-codegen:$moshiVersion"
 
     testImplementation 'junit:junit:4.13.2'
-    testImplementation 'org.robolectric:robolectric:4.8.1'
+    testImplementation 'org.robolectric:robolectric:4.9'
     debugImplementation 'com.facebook.stetho:stetho-okhttp3:1.6.0'
 }