Update dependency androidx.test.ext:junit to v1.2.1

Author: renovate[bot]

build.gradle

@@ -26,7 +26,7 @@ buildscript {
             androidxCursorAdapter: 'androidx.cursoradapter:cursoradapter:1.0.0',
             androidxExifInterface: 'androidx.exifinterface:exifinterface:1.3.3',
             androidxFragment     : 'androidx.fragment:fragment:1.4.0',
-            androidxJunit        : 'androidx.test.ext:junit:1.1.3',
+            androidxJunit        : 'androidx.test.ext:junit:1.2.1',
             androidxLifecycle    : 'androidx.lifecycle:lifecycle-common:2.4.0',
             androidxStartup      : 'androidx.startup:startup-runtime:1.1.0',
             androidxTestRunner   : 'androidx.test:runner:1.4.0',