AndroidCommonTests minsdk bump feom 19 to 21

Change-Id: I05a2a7de81d8202f0f996f599bd91da80501abf6
Bug:340711546
diff --git a/common/tests/Android.bp b/common/tests/Android.bp
index 8738a5d..1e8a24b 100644
--- a/common/tests/Android.bp
+++ b/common/tests/Android.bp
@@ -21,7 +21,7 @@
     name: "AndroidCommonTests",
     certificate: "platform",
     libs: ["android.test.runner.stubs"],
-    sdk_version: "19",
+    sdk_version: "21",
     srcs: ["src/**/*.java"],
     static_libs: [
         "android-common",