chore: enable gapic v2 and proto annotation for Web Security Scanner v1alpha API.

[yoshi-automation]

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[codecov]

Codecov Report

Merging #103 into master will not change coverage by %.
The diff coverage is 78.26%.

@@            Coverage Diff            @@
##             master     #103   +/-   ##
=========================================
  Coverage     76.01%   76.01%           
  Complexity      178      178           
=========================================
  Files            12       12           
  Lines          1584     1584           
  Branches         10       10           
=========================================
  Hits           1204     1204           
  Misses          346      346           
  Partials         34       34           

Impacted Files	Coverage Δ	Complexity Δ
...ityscanner/v1alpha/WebSecurityScannerSettings.java	13.20% <0.00%> (ø)	2.00 <0.00> (ø)
...tyscanner/v1alpha/stub/WebSecurityScannerStub.java	5.55% <0.00%> (ø)	1.00 <0.00> (ø)
...urityscanner/v1alpha/WebSecurityScannerClient.java	67.74% <60.00%> (ø)	42.00 <6.00> (ø)
...r/v1alpha/stub/WebSecurityScannerStubSettings.java	79.83% <88.88%> (ø)	22.00 <1.00> (ø)
...anner/v1alpha/stub/GrpcWebSecurityScannerStub.java	95.42% <100.00%> (ø)	19.00 <1.00> (ø)

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