Increase character limit for download notification strings

This is requested for Romanian translation.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=185359071

library/ui/src/main/res/values/strings.xml

@@ -38,12 +38,12 @@
   <string name="exo_controls_shuffle_description">Shuffle</string>
   <!-- Description for a media control button that toggles whether a video playback is fullscreen. [CHAR LIMIT=30] -->
   <string name="exo_controls_fullscreen_description">Fullscreen mode</string>
-  <!-- Shown in a notification or UI component to indicate a download is currently queued. [CHAR LIMIT=30] -->
+  <!-- Shown in a notification or UI component to indicate a download is currently queued. [CHAR LIMIT=40] -->
   <string name="exo_download_queued">Download queued</string>
-  <!-- Shown in a notification or UI component to indicate a download is currently downloading. [CHAR LIMIT=30] -->
+  <!-- Shown in a notification or UI component to indicate a download is currently downloading. [CHAR LIMIT=40] -->
   <string name="exo_downloading">Downloading</string>
-  <!-- Shown in a notification or UI component to indicate a download has finished downloading. [CHAR LIMIT=30] -->
+  <!-- Shown in a notification or UI component to indicate a download has finished downloading. [CHAR LIMIT=40] -->
   <string name="exo_download_completed">Download completed</string>
-  <!-- Shown in a notification or UI component to indicate a download has failed. [CHAR LIMIT=30] -->
+  <!-- Shown in a notification or UI component to indicate a download has failed. [CHAR LIMIT=40] -->
   <string name="exo_download_failed">Download failed</string>
 </resources>