[SPARK-12525] Fix fatal compiler warnings in Kinesis ASL due to @transient annotations

The Scala 2.11 SBT build currently fails for Spark 1.6.0 and master due to warnings about the `transient` annotation:

```
[error] [warn] /Users/joshrosen/Documents/spark/extras/kinesis-asl/src/main/scala/org/apache/spark/streaming/kinesis/KinesisBackedBlockRDD.scala:73: no valid targets for annotation on value sc - it is discarded unused. You may specify targets with meta-annotations, e.g. (transient param)
[error] [warn]     transient sc: SparkContext,
```

This fix implemented here is the same as what we did in #8433: remove the `transient` annotations when they are not necessary and replace use  `transient private val` in the remaining cases.

Author: Josh Rosen <joshrosen@databricks.com>

Closes #10479 from JoshRosen/fix-sbt-2.11.

extras/kinesis-asl/src/main/scala/org/apache/spark/streaming/kinesis/KinesisBackedBlockRDD.scala

@@ -70,26 +70,26 @@ class KinesisBackedBlockRDDPartition(
  */
 private[kinesis]
 class KinesisBackedBlockRDD[T: ClassTag](
-    @transient sc: SparkContext,
+    sc: SparkContext,
     val regionName: String,
     val endpointUrl: String,
-    @transient blockIds: Array[BlockId],
+    @transient private val _blockIds: Array[BlockId],
     @transient val arrayOfseqNumberRanges: Array[SequenceNumberRanges],
-    @transient isBlockIdValid: Array[Boolean] = Array.empty,
+    @transient private val isBlockIdValid: Array[Boolean] = Array.empty,
     val retryTimeoutMs: Int = 10000,
     val messageHandler: Record => T = KinesisUtils.defaultMessageHandler _,
     val awsCredentialsOption: Option[SerializableAWSCredentials] = None
-  ) extends BlockRDD[T](sc, blockIds) {
+  ) extends BlockRDD[T](sc, _blockIds) {
 
-  require(blockIds.length == arrayOfseqNumberRanges.length,
+  require(_blockIds.length == arrayOfseqNumberRanges.length,
     "Number of blockIds is not equal to the number of sequence number ranges")
 
   override def isValid(): Boolean = true
 
   override def getPartitions: Array[Partition] = {
-    Array.tabulate(blockIds.length) { i =>
+    Array.tabulate(_blockIds.length) { i =>
       val isValid = if (isBlockIdValid.length == 0) true else isBlockIdValid(i)
-      new KinesisBackedBlockRDDPartition(i, blockIds(i), isValid, arrayOfseqNumberRanges(i))
+      new KinesisBackedBlockRDDPartition(i, _blockIds(i), isValid, arrayOfseqNumberRanges(i))
     }
   }
 

extras/kinesis-asl/src/main/scala/org/apache/spark/streaming/kinesis/KinesisInputDStream.scala

@@ -30,7 +30,7 @@ import org.apache.spark.streaming.scheduler.ReceivedBlockInfo
 import org.apache.spark.streaming.{Duration, StreamingContext, Time}
 
 private[kinesis] class KinesisInputDStream[T: ClassTag](
-    @transient _ssc: StreamingContext,
+    _ssc: StreamingContext,
     streamName: String,
     endpointUrl: String,
     regionName: String,