NullPointerException in CronetDataSource constructor

When calling CronetDataSourceFactory.createDataSourceInteral, a null pointer
is passed as clock to the CronetDataSource constructor which in turn throws a
NullPointerException. Can be prevented by using other constructor without
clock parameter.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=153470874

extensions/cronet/src/main/java/com/google/android/exoplayer2/ext/cronet/CronetDataSourceFactory.java

@@ -72,7 +72,7 @@ public final class CronetDataSourceFactory extends BaseFactory {
   protected CronetDataSource createDataSourceInternal(HttpDataSource.RequestProperties
       defaultRequestProperties) {
     return new CronetDataSource(cronetEngine, executor, contentTypePredicate, transferListener,
-        connectTimeoutMs, readTimeoutMs, resetTimeoutOnRedirects, null, defaultRequestProperties);
+        connectTimeoutMs, readTimeoutMs, resetTimeoutOnRedirects, defaultRequestProperties);
   }
 
 }