[BEAM-8691] Upgrading the dependency com.google.cloud.bigtable:bigtable-client-core

[suztomo]

Upgrading the dependency com.google.cloud.bigtable:bigtable-client-core to the latest version 1.12.1.

https://issues.apache.org/jira/browse/BEAM-8691

---

Thank you for your contribution! Follow this checklist to help us incorporate your contribution quickly and easily:

• Choose reviewer(s) and mention them in a comment (R: @username).
• Format the pull request title like [BEAM-XXX] Fixes bug in ApproximateQuantiles, where you replace BEAM-XXX with the appropriate JIRA issue, if applicable. This will automatically link the pull request to the issue.
• If this contribution is large, please file an Apache Individual Contributor License Agreement.

See the Contributor Guide for more tips on how to make review process smoother.

Post-Commit Tests Status (on master branch)

Lang	SDK	Apex	Dataflow	Flink	Gearpump	Samza	Spark
Go		---	---		---	---
Java
Python		---			---	---
XLang	---	---	---		---	---	---

Pre-Commit Tests Status (on master branch)

---	Java	Python	Go	Website
Non-portable
Portable	---		---	---

See .test-infra/jenkins/README for trigger phrase, status and link of all Jenkins jobs.

[suztomo]

Run Java PreCommit

[suztomo]

I'll need more to understand org.apache.beam.sdk.io.gcp.GcpApiSurfaceTest https://issues.apache.org/jira/browse/BEAM-8691

Expected: API surface to include only:
	Classes in package "com.google.api.core"
	Classes in package "com.google.api.client.googleapis"
	Classes in package "com.google.api.client.http"
	Classes in package "com.google.api.client.json"
	Classes in package "com.google.api.client.util"
	Classes in package "com.google.api.services.bigquery.model"
	Classes in package "com.google.auth"
	Classes in package "com.google.bigtable.admin.v2"
	Classes in package "com.google.bigtable.v2"
	Classes in package "com.google.cloud.bigquery.storage.v1beta1"
	Classes in package "com.google.cloud.bigtable.config"
	Classes in package "com.google.cloud.bigtable.data"
	Classes in package "com.google.spanner.v1"
	<class com.google.api.gax.rpc.ApiException>
	<interface com.google.api.gax.longrunning.OperationFuture>
	<interface com.google.api.gax.longrunning.OperationSnapshot>
	<interface com.google.api.gax.paging.Page>
	<interface com.google.api.gax.retrying.RetryingFuture>
	<class com.google.api.gax.retrying.RetrySettings>
	<class com.google.api.gax.retrying.RetrySettings$Builder>
	<class com.google.api.gax.retrying.TimedAttemptSettings>
	<class com.google.api.gax.retrying.TimedAttemptSettings$Builder>
	<interface com.google.api.gax.rpc.StatusCode>
	<class com.google.api.gax.rpc.StatusCode$Code>
	<interface com.google.api.resourcenames.ResourceName>
	<class com.google.cloud.bigtable.grpc.BigtableClusterName>
	<class com.google.cloud.bigtable.grpc.BigtableInstanceName>
	<class com.google.cloud.bigtable.grpc.BigtableTableName>
	<class com.google.cloud.BaseServiceException>
	<class com.google.cloud.BaseServiceException$Error>
	<class com.google.cloud.BaseServiceException$ExceptionData>
	<class com.google.cloud.BaseServiceException$ExceptionData$Builder>
	<class com.google.cloud.RetryHelper$RetryHelperException>
	<class com.google.cloud.grpc.BaseGrpcServiceException>
	<class com.google.cloud.ByteArray>
	<class com.google.cloud.Date>
	<class com.google.cloud.Timestamp>
	Classes in package "com.google.cloud.spanner"
	Classes in package "com.google.spanner.admin.database.v1"
	Classes in package "com.google.datastore.v1"
	Classes in package "com.google.protobuf"
	Classes in package "com.google.type"
	Classes in package "com.fasterxml.jackson.annotation"
	Classes in package "com.fasterxml.jackson.core"
	Classes in package "com.fasterxml.jackson.databind"
	Classes in package "io.grpc"
	Classes in package "java"
	Classes in package "javax"
	Classes in package "org.apache.avro"
	Classes in package "org.apache.beam"
	Classes in package "org.apache.commons.logging"
	Classes in package "org.codehaus.jackson"
	Classes in package "org.joda.time"
	Classes in package "org.threeten.bp"
	
     but: The following white-listed scopes did not have matching classes on the API surface:
	No <interface com.google.api.resourcenames.ResourceName>
	No Classes in package "com.google.bigtable.admin.v2"
	No Classes in package "com.google.cloud.bigtable.data"