Input-related documentation fixes.

Fix a few typos in InputFilter.  Fix reference in InputEvent currently
causing public documentation breakage.

Change-Id: I6268ad165f11d4d9d5a4a66ed97f1538e174cf84
diff --git a/core/java/android/view/InputFilter.java b/core/java/android/view/InputFilter.java
index c25b87b..4aba30c 100644
--- a/core/java/android/view/InputFilter.java
+++ b/core/java/android/view/InputFilter.java
@@ -40,7 +40,7 @@
  * <li>Input events are then asynchronously delivered to the input filter's
  * {@link #onInputEvent(InputEvent)} method instead of being enqueued for dispatch to
  * applications as usual.  The input filter only receives input events that were
- * generated by input device; the input filter will not receive input events that were
+ * generated by an input device; the input filter will not receive input events that were
  * injected into the system by other means, such as by instrumentation.</li>
  * <li>The input filter processes and optionally transforms the stream of events.  For example,
  * it may transform a sequence of motion events representing an accessibility gesture into
@@ -68,7 +68,7 @@
  * The input filter must take into account the fact that the input events coming from different
  * devices or even different sources all consist of distinct streams of input.
  * Use {@link InputEvent#getDeviceId()} and {@link InputEvent#getSource()} to identify
- * the source of the event and its semantics.  There are be multiple sources of keys,
+ * the source of the event and its semantics.  There may be multiple sources of keys,
  * touches and other input: they must be kept separate.
  * </p>
  * <h3>Policy flags</h3>
@@ -88,7 +88,7 @@
  * The input filter should clear its internal state about the gesture and then send key or
  * motion events to the dispatcher to cancel any keys or pointers that are down.
  * </p><p>
- * Corollary: Events that set sent to the dispatcher should usually include the
+ * Corollary: Events that get sent to the dispatcher should usually include the
  * {@link WindowManagerPolicy#FLAG_PASS_TO_USER} flag.  Otherwise, they will be dropped!
  * </p><p>
  * It may be prudent to disable automatic key repeating for synthetic key events