Add bulk subscriber over gRPC to examples (#871)

* original version of bulk subscriber over gPRC

Signed-off-by: MregXN <[email protected]>

* cover validation to grpc subscriber

Signed-off-by: MregXN <[email protected]>

* modify README of pubsub example

Signed-off-by: MregXN <[email protected]>

* re-trigger validation to pass flaky test

Signed-off-by: MregXN <[email protected]>

* Update BulkSubscriberGrpcService.java

Signed-off-by: Artur Souza <[email protected]>

* modify README.md

Signed-off-by: MregXN <[email protected]>

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Signed-off-by: MregXN <[email protected]>
Signed-off-by: Artur Souza <[email protected]>
Co-authored-by: Artur Souza <[email protected]>
Co-authored-by: Mukundan Sundararajan <[email protected]>
Co-authored-by: Artur Souza <[email protected]>
Co-authored-by: Cassie Coyle <[email protected]>

Author: 4 people