samples(spanner): update proto generated files

Author: harshachinta

samples/snippets/src/main/resources/com/example/spanner/README.md

@@ -0,0 +1,6 @@
+#### To generate SingerProto.java and descriptors.pb file from singer.proto using `protoc`
+```shell
+cd samples/snippets/src/main/resources/
+protoc --proto_path=com/example/spanner/ --include_imports --descriptor_set_out=com/example/spanner/descriptors.pb
+ --java_out=. com/example/spanner/singer.proto
+```

samples/snippets/src/main/resources/com/example/spanner/singer.proto

@@ -0,0 +1,21 @@
+syntax = "proto3";
+
+package examples.spanner.music;
+
+option java_package = "com.example.spanner";
+option java_outer_classname = "SingerProto";
+option java_multiple_files = false;
+
+message SingerInfo {
+ optional int64 singer_id = 1;
+ optional string birth_date = 2;
+ optional string nationality = 3;
+ optional Genre genre = 4;
+}
+
+enum Genre {
+ POP = 0;
+ JAZZ = 1;
+ FOLK = 2;
+ ROCK = 3;
+}