[SPARK-23956][YARN] Use effective RPC port in AM registration

[gerashegalov]

What changes were proposed in this pull request?

We propose not to hard-code the RPC port in the AM registration.

How was this patch tested?

Tested application reports from a pseudo-distributed cluster

18/04/10 14:56:21 INFO Client:
client token: N/A
diagnostics: N/A
ApplicationMaster host: localhost
ApplicationMaster RPC port: 58338
queue: default
start time: 1523397373659
final status: UNDEFINED
tracking URL: http://localhost:8088/proxy/application_1523370127531_0016/

[vanzin]

ok to test

[SparkQA]

Test build #89222 has finished for PR 21047 at commit cc67ccb.

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

[jerryshao]

LGTM.

[jerryshao]

Jenkins, retest this please.

[SparkQA]

Test build #89384 has finished for PR 21047 at commit cc67ccb.

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

[jerryshao]

Merging to master. Thanks!

[gerashegalov]

thank you for review and commit @jerryshao !