bump required versions for objC examples

due to protobuf bumping their required versions here: protocolbuffers/protobuf#10652

src/objective-c/examples/InterceptorSample/Podfile

@@ -1,4 +1,4 @@
-platform :ios, '9.0'
+platform :ios, '10.0'
 
 install! 'cocoapods', :deterministic_uuids => false
 

src/objective-c/examples/RemoteTestClient/RemoteTest.podspec

@@ -7,10 +7,10 @@ Pod::Spec.new do |s|
   s.summary = 'RemoteTest example'
   s.source = { :git => 'https://github.com/grpc/grpc.git' }
 
-  s.ios.deployment_target = '9.0'
-  s.osx.deployment_target = '10.10'
-  s.tvos.deployment_target = '10.0'
-  s.watchos.deployment_target = '4.0'
+  s.ios.deployment_target = '10.0'
+  s.osx.deployment_target = '10.12'
+  s.tvos.deployment_target = '12.0'
+  s.watchos.deployment_target = '6.0'
 
   # Run protoc with the Objective-C and gRPC plugins to generate protocol messages and gRPC clients.
   s.dependency "!ProtoCompiler-gRPCPlugin"

src/objective-c/examples/Sample/Podfile

@@ -1,5 +1,5 @@
 source 'https://github.com/CocoaPods/Specs.git'
-platform :ios, '9.0'
+platform :ios, '10.0'
 
 install! 'cocoapods', :deterministic_uuids => false
 

src/objective-c/examples/SwiftSample/Podfile

@@ -1,5 +1,5 @@
 source 'https://github.com/CocoaPods/Specs.git'
-platform :ios, '9.0'
+platform :ios, '10.0'
 
 install! 'cocoapods', :deterministic_uuids => false
 

src/objective-c/examples/watchOS-sample/Podfile

@@ -14,11 +14,11 @@ def grpc_deps
 end
 
 target 'watchOS-sample' do
-platform :ios, '9.0'
+platform :ios, '10.0'
   grpc_deps
 end
 
 target 'watchOS-sample WatchKit Extension' do
-platform :watchos, '4.0'
+platform :watchos, '6.0'
   grpc_deps
 end