Remove redundant default broker configurations

[Jackie-Jiang]

• Remove config based routing configs because the config based
  routing was removed long time ago
• Remove HelixBrokerStarter.getZkAddressForBroker() because it
  does not apply to the current implementation
• Replace config key strings with constants
• Change timeout for default broker and broker in integration
  test to 60s
• Replace PropertiesConfiguration with light weight
  BaseConfiguration if not read from config file

[codecov-io]

Codecov Report

Merging #4106 into master will decrease coverage by 0.03%.
The diff coverage is 73.33%.

@@             Coverage Diff              @@
##             master    #4106      +/-   ##
============================================
- Coverage     66.88%   66.84%   -0.04%     
  Complexity       20       20              
============================================
  Files          1037     1036       -1     
  Lines         51444    51417      -27     
  Branches       7193     7190       -3     
============================================
- Hits          34407    34371      -36     
- Misses        14664    14683      +19     
+ Partials       2373     2363      -10

Impacted Files	Coverage Δ	Complexity Δ
.../pinot/broker/broker/helix/HelixBrokerStarter.java	76.66% <73.33%> (+0.15%)	0 <0> (ø)	⬇️
...ller/validation/OfflineSegmentIntervalChecker.java	26.43% <0%> (-48.28%)	0% <0%> (ø)
...apache/pinot/common/metrics/ValidationMetrics.java	43.47% <0%> (-36.24%)	0% <0%> (ø)
...egation/function/customobject/MinMaxRangePair.java	75.86% <0%> (-24.14%)	0% <0%> (ø)
...lix/EmptyBrokerOnlineOfflineStateModelFactory.java	86.66% <0%> (-13.34%)	0% <0%> (ø)
...mpl/dictionary/DoubleOffHeapMutableDictionary.java	69.09% <0%> (-9.1%)	0% <0%> (ø)
...nsport/netty/PooledNettyClientResourceManager.java	85.41% <0%> (-4.17%)	0% <0%> (ø)
...e/operator/dociditerators/BitmapDocIdIterator.java	60.71% <0%> (-3.58%)	0% <0%> (ø)
...impl/dictionary/FloatOffHeapMutableDictionary.java	85.45% <0%> (-1.82%)	0% <0%> (ø)
...ata/manager/realtime/RealtimeTableDataManager.java	41.17% <0%> (-1.48%)	0% <0%> (ø)
... and 28 more

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[snleee]

LGTM. Thanks for cleaning up