tests: Move to Android.bp.

Also separate libupdater_defaults out to be shareable.

It turns out the `data` property in `cc_test` doesn't follow symlinks as
LOCAL_TEST_DATA does in Android.mk. This CL creates a filegroup in
top-level Android.bp in order to pick up the testdata for ResourcesTest.

Test: `mmma -j bootable/recovery` with aosp_marlin-userdebug
Test: Run recovery_{unit,component,manual}_test on marlin.
Test: Run recovery_host_test.
Change-Id: I4532ab25aeb83c0b0baa8051d5fe34ba7b910a35
diff --git a/Android.bp b/Android.bp
index e97f71d..53b74dc 100644
--- a/Android.bp
+++ b/Android.bp
@@ -291,3 +291,11 @@
         "recovery-refresh.rc",
     ],
 }
+
+filegroup {
+    name: "res-testdata",
+
+    srcs: [
+        "res-*/images/*_text.png",
+    ],
+}