Update sample and test versions to -pre1.1

To use the 3.0.0-beta-4 version of protoc, which has the fix for oneofs
when using dynamic frameworks.
diff --git "a/src/objective-c/\041ProtoCompiler.podspec" "b/src/objective-c/\041ProtoCompiler.podspec"
index 56aacc3..45fc135 100644
--- "a/src/objective-c/\041ProtoCompiler.podspec"
+++ "b/src/objective-c/\041ProtoCompiler.podspec"
@@ -36,7 +36,7 @@
   # exclamation mark ensures that other "regular" pods will be able to find it as it'll be installed
   # before them.
   s.name     = '!ProtoCompiler'
-  v = '3.0.0-beta-3.1'
+  v = '3.0.0-beta-4'
   s.version  = v
   s.summary  = 'The Protobuf Compiler (protoc) generates Objective-C files from .proto files'
   s.description = <<-DESC
@@ -120,7 +120,7 @@
   repo_root = '../..'
   plugin = 'grpc_objective_c_plugin'
   s.prepare_command = <<-CMD
-    if [ ! -f protoc ]; then
+    if [ ! -f bin/protoc ]; then
       cd #{repo_root}
       # This will build protoc from the Protobuf submodule of gRPC, and put it in
       # #{repo_root}/bins/opt/protobuf.
@@ -129,7 +129,9 @@
       # _we do not want_. Find a way for this to always build from source.
       make #{plugin}
       cd -
+    else
+      mv bin/protoc .
+      mv include/google .
     fi
   CMD
-
 end