feat: add BatchWrite, Partition and Index Management to generated clients

[yoshi-automation]

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[codecov]

Codecov Report

Merging #253 into master will increase coverage by 0.61%.
The diff coverage is 83.08%.

@@             Coverage Diff              @@
##             master     #253      +/-   ##
============================================
+ Coverage     73.01%   73.62%   +0.61%     
- Complexity     1035     1036       +1     
============================================
  Files            64       64              
  Lines          5443     5695     +252     
  Branches        618      621       +3     
============================================
+ Hits           3974     4193     +219     
- Misses         1271     1307      +36     
+ Partials        198      195       -3     

Impacted Files	Coverage Δ	Complexity Δ
...gle/cloud/firestore/v1/FirestoreAdminSettings.java	13.20% <0.00%> (-2.35%)	2.00 <0.00> (ø)
...m/google/cloud/firestore/v1/FirestoreSettings.java	15.78% <0.00%> (-1.20%)	4.00 <0.00> (ø)
...le/cloud/firestore/v1/stub/FirestoreAdminStub.java	5.88% <0.00%> (-2.46%)	1.00 <0.00> (ø)
.../google/cloud/firestore/v1/stub/FirestoreStub.java	5.26% <0.00%> (-0.99%)	1.00 <0.00> (ø)
...gle/cloud/firestore/v1beta1/FirestoreSettings.java	13.20% <0.00%> (ø)	2.00 <0.00> (ø)
...le/cloud/firestore/v1beta1/stub/FirestoreStub.java	6.25% <0.00%> (ø)	1.00 <0.00> (ø)
...oogle/cloud/firestore/v1/FirestoreAdminClient.java	57.46% <50.00%> (-2.38%)	38.00 <23.00> (ø)
.../firestore/v1beta1/stub/FirestoreStubSettings.java	82.35% <79.68%> (ø)	23.00 <5.00> (ø)
...cloud/firestore/v1/stub/FirestoreStubSettings.java	82.10% <81.57%> (-0.26%)	25.00 <2.00> (+2.00)	⬇️
...com/google/cloud/firestore/v1/FirestoreClient.java	82.92% <90.90%> (+5.78%)	40.00 <4.00> (+3.00)
... and 8 more

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[BenWhitehead]

Blocked penting switch to v2 work on master

[BenWhitehead]

Superseded by #300