chore: make Partition class getters public (#2195)

Make getters in Partition class public so that they can be accessed outside com.google.cloud.spanner package.

Author: rajatbhatta

README.md

@@ -56,13 +56,13 @@ implementation 'com.google.cloud:google-cloud-spanner'
 If you are using Gradle without BOM, add this to your dependencies:
 
 ```Groovy
-implementation 'com.google.cloud:google-cloud-spanner:6.33.0'
+implementation 'com.google.cloud:google-cloud-spanner:6.34.0'
 ```
 
 If you are using SBT, add this to your dependencies:
 
 ```Scala
-libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "6.33.0"
+libraryDependencies += "com.google.cloud" % "google-cloud-spanner" % "6.34.0"
 ```
 
 ## Authentication

google-cloud-spanner/src/main/java/com/google/cloud/spanner/Partition.java

@@ -92,7 +92,7 @@ static Partition createQueryPartition(
     return new Partition(partitionToken, partitionOptions, statement, queryOption);
   }
 
-  ByteString getPartitionToken() {
+  public ByteString getPartitionToken() {
     return partitionToken;
   }