Use more precise names for protobuf and nano

io.grpc.nano sort of seems like a "small" version of grpc-java. And
io.grpc.proto could also mean multiple things. Using "protobuf"
and "protobuf nano" gets us consistent names that are still
understandable, predictable, and more similar to protobuf project
itself.
diff --git a/settings.gradle b/settings.gradle
index a36c5e9..a98b52e 100644
--- a/settings.gradle
+++ b/settings.gradle
@@ -4,7 +4,7 @@
 include ":grpc-auth"
 include ":grpc-okhttp"
 include ":grpc-protobuf"
-include ":grpc-nano"
+include ":grpc-protobuf-nano"
 include ":grpc-netty"
 include ":grpc-testing"
 include ":grpc-compiler"
@@ -18,7 +18,7 @@
 project(':grpc-auth').projectDir = "$rootDir/auth" as File
 project(':grpc-okhttp').projectDir = "$rootDir/okhttp" as File
 project(':grpc-protobuf').projectDir = "$rootDir/protobuf" as File
-project(':grpc-nano').projectDir = "$rootDir/nano" as File
+project(':grpc-protobuf-nano').projectDir = "$rootDir/nano" as File
 project(':grpc-netty').projectDir = "$rootDir/netty" as File
 project(':grpc-testing').projectDir = "$rootDir/testing" as File
 project(':grpc-compiler').projectDir = "$rootDir/compiler" as File