Fix bug when traceparent is too small

[dengliming]

for #2038

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[codecov-commenter]

Codecov Report

Merging #2047 into master will decrease coverage by 0.02%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##             master    #2047      +/-   ##
============================================
- Coverage     83.06%   83.04%   -0.03%     
+ Complexity     2251     2249       -2     
============================================
  Files           319      319              
  Lines         10529    10528       -1     
  Branches       1048     1047       -1     
============================================
- Hits           8746     8743       -3     
- Misses         1446     1447       +1     
- Partials        337      338       +1     

Impacted Files	Coverage Δ	Complexity Δ
...implcore/trace/propagation/TraceContextFormat.java	94.02% <100.00%> (-0.09%)	15.00 <0.00> (-1.00)
...pencensus/implcore/trace/RecordEventsSpanImpl.java	92.34% <0.00%> (-1.03%)	49.00% <0.00%> (-1.00%)

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[dengliming]

@nilebox Can you review these changes? This seems to be a higher priority during the opencensus transition to Opentelemetry.

[nilebox]

Could you add a unit test reproducing the issue #2038 and confirming it's fixed by this change?

[dengliming]

I haven't find a recurrence here, but anyway, there is something wrong with the logic of this code, right?

[nilebox]

Unfortunately, I'm not familiar with this code.

I do agree that the expression seems to have a redundant duplicate condition, though removing the first check may lead to some other issue since when it's "false" the remaining conditions won't get executed.
So I suggest to add a test reproducing the issue this change is supposed to fix.