fix: throw jobexception for invalid multiple statements query

[stephaniewang526]

Fixes b/163347694

[codecov]

Codecov Report

Merging #732 into master will increase coverage by 0.08%.
The diff coverage is 87.50%.

@@             Coverage Diff              @@
##             master     #732      +/-   ##
============================================
+ Coverage     81.07%   81.15%   +0.08%     
- Complexity     1236     1240       +4     
============================================
  Files            78       78              
  Lines          6334     6341       +7     
  Branches        705      708       +3     
============================================
+ Hits           5135     5146      +11     
+ Misses          833      828       -5     
- Partials        366      367       +1     

Impacted Files	Coverage Δ	Complexity Δ
...y/src/main/java/com/google/cloud/bigquery/Job.java	85.90% <87.50%> (-0.01%)	34.00 <0.00> (+2.00)	⬇️
...n/java/com/google/cloud/bigquery/JobException.java	83.33% <0.00%> (+83.33%)	2.00% <0.00%> (+2.00%)

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[shollyman]

Could you expand on what's going on here in the PR description? I see you're adding a new raise to the reload, is this to match behavior from something else?

[stephaniewang526]

Could you expand on what's going on here in the PR description? I see you're adding a new raise to the reload, is this to match behavior from something else?

Indeed! Customer noticed that we are throwing Exception in invalid single-statement scenario but not invalid Multi-statement scenario. We are trying to make the behavior consistent here.