Clean up icon names.

MyTracks/res/layout/about.xml

@@ -22,7 +22,7 @@ limitations under the License.
     android:orientation="vertical"
     android:padding="8dp" >
     <TextView
-      android:drawableLeft="@drawable/arrow_icon"
+      android:drawableLeft="@drawable/my_tracks_icon"
       android:text="@string/about_copyright_notice"
       style="@style/TextMedium.WithIcon" />
     <TextView

MyTracks/res/layout/help.xml

@@ -29,7 +29,7 @@ limitations under the License.
         android:layout_height="wrap_content"
         android:layout_width="wrap_content"
         android:scaleType="fitStart"
-        android:src="@drawable/arrow_icon" />
+        android:src="@drawable/my_tracks_icon" />
       <TextView
         android:text="@string/help_my_tracks_question"
         style="@style/HelpQuestion" />

MyTracks/res/layout/track_widget.xml

@@ -15,7 +15,7 @@ See the License for the specific language governing permissions and
 limitations under the License.
 -->
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
-  android:background="@drawable/appwidget_background"
+  android:background="@drawable/app_widget_background"
   android:layout_height="fill_parent"
   android:layout_width="fill_parent"
   android:paddingBottom="5dp"
@@ -30,7 +30,7 @@ limitations under the License.
     android:layout_width="wrap_content"
     android:paddingLeft="10dp"
     android:paddingRight="10dp"
-    android:src="@drawable/appwidget_button_disabled" />
+    android:src="@drawable/app_widget_button_disabled" />
   <LinearLayout
     android:clickable="true"
     android:id="@+id/appwidget_track_statistics"

MyTracks/res/layout/upload_service_chooser.xml

@@ -24,7 +24,7 @@ limitations under the License.
     <TableRow android:id="@+id/send_google_maps_row" >
       <ImageView
         android:contentDescription="@string/send_google_maps"
-        android:src="@drawable/maps_icon"
+        android:src="@drawable/google_maps_icon"
         style="@style/UploadServiceChooserImageView" />
       <CheckBox
         android:id="@+id/send_google_maps"
@@ -50,7 +50,7 @@ limitations under the License.
     <TableRow android:id="@+id/send_google_fusion_tables_row" >
       <ImageView
         android:contentDescription="@string/send_google_fusion_tables"
-        android:src="@drawable/googledocs_icon"
+        android:src="@drawable/google_fusion_tables_icon"
         style="@style/UploadServiceChooserImageView" />
       <CheckBox
         android:id="@+id/send_google_fusion_tables"
@@ -60,7 +60,7 @@ limitations under the License.
     <TableRow android:id="@+id/send_google_docs_row" >
       <ImageView
         android:contentDescription="@string/send_google_docs"
-        android:src="@drawable/googledocs_icon"
+        android:src="@drawable/google_docs_icon"
         style="@style/UploadServiceChooserImageView" />
       <CheckBox
         android:id="@+id/send_google_docs"