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

[JoshRosen]

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.

[SparkQA]

Test build #48330 has finished for PR 10479 at commit 0b79c39.

• This patch fails to build.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #48332 has finished for PR 10479 at commit 70e7032.

• This patch fails to build.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #48333 has finished for PR 10479 at commit afe11f2.

• This patch fails to build.
• This patch merges cleanly.
• This patch adds no public classes.

[SparkQA]

Test build #48334 has finished for PR 10479 at commit 0a3f671.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.

[srowen]

LGTM

[JoshRosen]

@skyluc @rxin, according to #8433 "if the class parameter are used in methods, then fields are created." I'm not sure how this applies in this case, where blockIds is also the name of a field in the superclass. In #8433, it looks like the fix was just to rename blockIds to _blockIds in order to avoid any ambiguity (see c1bc4f4#diff-b936e296c84502986961fb815d642458L64). Therefore, I'm going to make the same fix here for consistency's sake.

[JoshRosen]

I'm only planning to merge this into 2.0.0.

[rxin]

LGTM

[JoshRosen]

Jenkins, retest this please.

[JoshRosen]

Jenkins, retest this please.

[SparkQA]

Test build #48376 has finished for PR 10479 at commit 422ef49.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds no public classes.