Upgrade to new Android SDK.

tools/android/eclipse/.classpath

Index: tools/android/eclipse/.classpath
diff --git a/tools/android/eclipse/.classpath b/tools/android/eclipse/.classpath
index 520b42a4eac58ee7f152b8d4292dde2b28bec956..5197571f3b403fcf8c6f42065a355430389c2ef5 100644
--- a/tools/android/eclipse/.classpath
+++ b/tools/android/eclipse/.classpath
@@ -212,13 +212,13 @@ to the classpath for downstream development. See "additional_entries" below.
     <classpathentry kind="src" path="out/Debug/java_proto/test_support_proto_java/src"/>
     <classpathentry kind="src" path="out/Debug/remoting_apk/gen"/>
     <classpathentry kind="lib" path="third_party/android_tools/sdk/extras/google/gcm/gcm-client/dist/gcm.jar" sourcepath="third_party/android_tools/sdk/extras/google/gcm/gcm-client/src"/>
-    <classpathentry kind="lib" path="third_party/android_tools/sdk/platforms/android-23/android.jar" sourcepath="third_party/android_tools/sdk/sources/">
+    <classpathentry kind="lib" path="third_party/android_tools/sdk/platforms/android-24/android.jar" sourcepath="third_party/android_tools/sdk/sources/">
         <attributes>
             <attribute name="javadoc_location" value="http://developer.android.com/reference/"/>
         </attributes>
     </classpathentry>
-    <classpathentry kind="lib" path="third_party/android_tools/sdk/platforms/android-23/data/layoutlib.jar" sourcepath="third_party/android_tools/sdk/sources/"/>
-    <classpathentry kind="lib" path="third_party/android_tools/sdk/platforms/android-23/uiautomator.jar" sourcepath="third_party/android_tools/sdk/sources"/>
+    <classpathentry kind="lib" path="third_party/android_tools/sdk/platforms/android-24/data/layoutlib.jar" sourcepath="third_party/android_tools/sdk/sources/"/>
+    <classpathentry kind="lib" path="third_party/android_tools/sdk/platforms/android-24/uiautomator.jar" sourcepath="third_party/android_tools/sdk/sources"/>
     <classpathentry kind="lib" path="third_party/android_tools/sdk/extras/android/support/design/libs/android-support-design.jar" sourcepath="third_party/android_tools/sdk/sources"/>
     <classpathentry kind="lib" path="third_party/android_tools/sdk/extras/android/support/v7/mediarouter/libs/android-support-v7-mediarouter.jar" sourcepath="third_party/android_tools/sdk/sources"/>
     <classpathentry kind="lib" path="third_party/android_tools/sdk/extras/android/support/v7/recyclerview/libs/android-support-v7-recyclerview.jar" sourcepath="third_party/android_tools/sdk/sources"/>