docs: Fix phrasing for BroadcastReceiver.PendingResult

Phrasing was a little garbled, I felt safe cleaning it up but please
correct me if I got it wrong!

NO_TEST , fixes a doc bug (no code edits).

Test: [go/abtd docs build]
Fixes: 289051151
Change-Id: Ibe22b10335a100c5d25d31bebc02dca439dca5f6
diff --git a/core/java/android/content/BroadcastReceiver.java b/core/java/android/content/BroadcastReceiver.java
index 3d76b28..d7195a7 100644
--- a/core/java/android/content/BroadcastReceiver.java
+++ b/core/java/android/content/BroadcastReceiver.java
@@ -65,7 +65,7 @@
      * thread of your app.
      *
      * <p>Note on threading: the state inside of this class is not itself
-     * thread-safe, however you can use it from any thread if you properly
+     * thread-safe. However, you can use it from any thread if you make
      * sure that you do not have races.  Typically this means you will hand
      * the entire object to another thread, which will be solely responsible
      * for setting any results and finally calling {@link #finish()}.