Updating Checkstyle config and fixing warnings

[ldanielmadariaga]

Updating Checkstyle config so it: 1) Complies with 'CHECKSTYLE:OFF' commands 2) Stops enforcing multiline Javadocs as Google format collapses these when short enough.

Also fixed checkstyle and formatting warnings for offending classes.

[codecov[bot]]

Codecov Report

Merging #135 into dev will decrease coverage by 0.02%. The diff coverage is 95.16%.

@@             Coverage Diff              @@
##                dev     #135      +/-   ##
============================================
- Coverage     75.78%   75.75%   -0.03%     
- Complexity      386      387       +1     
============================================
  Files            42       42              
  Lines          3543     3535       -8     
  Branches        278      278              
============================================
- Hits           2685     2678       -7     
+ Misses          761      760       -1     
  Partials         97       97

Impacted Files	Coverage Δ	Complexity Δ
.../cloud/pontem/AvroCloudSpannerDatabaseRestore.java	0% <ø> (ø)	0 <0> (ø)	:arrow_down:
...loud/pontem/FormatStructAsGenericRecordFnTest.java	100% <ø> (ø)	10 <0> (ø)	:arrow_down:
...oud/pontem/AvroCloudSpannerDatabaseBackupTest.java	100% <ø> (ø)	3 <0> (ø)	:arrow_down:
...tem/FormatSpannerTablesListStructAsTextFnTest.java	100% <ø> (ø)	4 <0> (ø)	:arrow_down:
...java/com/google/cloud/pontem/TableInformation.java	87.71% <ø> (ø)	16 <0> (ø)	:arrow_down:
.../pontem/SerializedCloudSpannerDatabaseRestore.java	0% <ø> (ø)	0 <0> (ø)	:arrow_down:
...rc/test/java/com/google/cloud/pontem/UtilTest.java	92.3% <ø> (ø)	4 <0> (ø)	:arrow_down:
...le/cloud/pontem/FormatSpannerStructAsStringFn.java	84.61% <ø> (ø)	2 <0> (ø)	:arrow_down:
...ud/pontem/FormatStringAsSpannerMutationFnTest.java	92% <ø> (ø)	9 <0> (ø)	:arrow_down:
...ntem/SerializedCloudSpannerDatabaseBackupTest.java	100% <ø> (ø)	3 <0> (ø)	:arrow_down:
... and 32 more