Check if thread is interrupted before opening connection

On an old version of okhttp, opening connection clears the thread interrupt flag silently. This is a workaround
to reduce the effect of the bug.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=161784435

library/core/src/main/java/com/google/android/exoplayer2/upstream/cache/CacheUtil.java

@@ -228,6 +228,9 @@ public final class CacheUtil {
         priorityTaskManager.proceed(priority);
       }
       try {
+        if (Thread.interrupted()) {
+          throw new InterruptedException();
+        }
         // Create a new dataSpec setting length to C.LENGTH_UNSET to prevent getting an error in
         // case the given length exceeds the end of input.
         dataSpec = new DataSpec(dataSpec.uri, dataSpec.postBody, absoluteStreamPosition,