Update AndroidX Test version to 1.2.1

Author: martenrebane

build.gradle

@@ -41,7 +41,7 @@ ext {
     androidxCardviewVersion = '1.0.0'
     androidxLocalBroadcastManagerVersion = '1.1.0'
     androidxTestCoreVersion = '1.5.0'
-    androidxTestVersion = '1.1.5'
+    androidxTestVersion = '1.2.1'
     androidxTestOrchestratorVersion = '1.5.1'
     androidxTestRulesVersion = '1.5.0'
     androidxTestEspressoVersion = '3.5.1'