chore: move generator into jdbc package

Author: olavloite

pom.xml

@@ -351,7 +351,7 @@
               <goal>java</goal>
             </goals>
             <configuration>
-              <mainClass>com.google.cloud.spanner.connection.ConnectionPropertiesFileGenerator</mainClass>
+              <mainClass>com.google.cloud.spanner.jdbc.ConnectionPropertiesFileGenerator</mainClass>
               <classpathScope>test</classpathScope>
               <skip>false</skip>
             </configuration>

src/test/java/com/google/cloud/spanner/connection/ConnectionPropertiesFileGenerator.java renamed to src/test/java/com/google/cloud/spanner/jdbc/ConnectionPropertiesFileGenerator.java

@@ -14,8 +14,10 @@
  * limitations under the License.
  */
 
-package com.google.cloud.spanner.connection;
+package com.google.cloud.spanner.jdbc;
 
+import com.google.cloud.spanner.connection.ConnectionPropertiesHelper;
+import com.google.cloud.spanner.connection.ConnectionProperty;
 import java.io.BufferedWriter;
 import java.io.FileWriter;
 import java.io.IOException;