Add PrepareUpdateService.

It's moved from PrepareStreamingService intent service.
Now PrepareUpdateService takes an UpdateConfig and
builds PayloadSpec for UpdateEngine for both streaming
and non-streaming update.

It allows us to do all preparations in intent service's
thread, without blocking UI.

We will also add checksum verification to
PrepareUpdateService.

Test: device, junit
Bug: 77150191
Change-Id: Iea69acd9aa41e17538c26aff60f7598093ca7744
diff --git a/updater_sample/tests/Android.bp b/updater_sample/tests/Android.bp
index e434405..806babd 100644
--- a/updater_sample/tests/Android.bp
+++ b/updater_sample/tests/Android.bp
@@ -24,6 +24,7 @@
 
     static_libs: [
         "androidx.test.runner",
+        "androidx.test.rules",
         "mockito-target-minus-junit4",
         "guava",
     ],