feat(bigtable): pass default app profile ID in quickstart

Update the quickstart example to explicitly configure the Table instance
with the "default" application profile ID using AppProfileIdOption.

Author: elinorli

google/cloud/bigtable/README.md

@@ -36,8 +36,10 @@ int main(int argc, char* argv[]) try {
   // Create a namespace alias to make the code easier to read.
   namespace cbt = ::google::cloud::bigtable;
 
-  cbt::Table table(cbt::MakeDataConnection(),
-                   cbt::TableResource(project_id, instance_id, table_id));
+  cbt::Table table(
+      cbt::MakeDataConnection(),
+      cbt::TableResource(project_id, instance_id, table_id),
+      google::cloud::Options{}.set<cbt::AppProfileIdOption>("default"));
 
   std::string row_key = "r1";
   std::string column_family = "cf1";

google/cloud/bigtable/quickstart/quickstart.cc

@@ -31,8 +31,10 @@ int main(int argc, char* argv[]) try {
   // Create a namespace alias to make the code easier to read.
   namespace cbt = ::google::cloud::bigtable;
 
-  cbt::Table table(cbt::MakeDataConnection(),
-                   cbt::TableResource(project_id, instance_id, table_id));
+  cbt::Table table(
+      cbt::MakeDataConnection(),
+      cbt::TableResource(project_id, instance_id, table_id),
+      google::cloud::Options{}.set<cbt::AppProfileIdOption>("default"));
 
   std::string row_key = "r1";
   std::string column_family = "cf1";