Changed setup_ios_native to support Apple Silicone

Homebrew installs packages differently depending on chip
architecture -- updated the setup script to reflect this difference.

setup/setup_ios_native.sh

@@ -7,14 +7,32 @@ source setup/setup_shared.sh
 OSX_MAJOR_VERSION=`sw_vers | grep ProductVersion | cut -d ':' -f 2 | cut -d '.' -f 1`
 echo "Found OSX major version" $OSX_MAJOR_VERSION
 
+# The Homebrew pac-man is installed in different locations, depending on whether the processor
+# is an Intel or Apple Silicone chip.  Intel uses x86_64, Apple chips are amd64, so we can
+# check the chip type using these hardware platforms.
+CHIP_ARC=`uname -m`
+INTEL="x86_64"
+APPLE_SILICONE="arm64"
+WORKING_DIR=""
+
+if [ $CHIP_ARC == $INTEL ]; then
+    echo "Found "$INTEL" chip"
+    WORKING_DIR="/usr/local/"
+else 
+    if [ $CHIP_ARC == $APPLE_SILICONE ]; then
+        echo "Found "$APPLE_SILICONE" chip"
+        WORKING_DIR="/opt/homebrew/"
+    fi
+fi
+
 CURR_RUBY_VERSION=`ruby --version | cut -d ' ' -f 2 | cut -d '.' -f 1-2`
 echo "Found ruby version "$CURR_RUBY_VERSION
 
 if [ $CURR_RUBY_VERSION == $RUBY_VERSION ]; then
     echo "Found ruby version "$CURR_RUBY_VERSION" expected "$RUBY_VERSION" no need to upgrade"
 else
-    if [ -x /usr/local/bin/brew ]; then
-        echo "Found brew installation with version" `/usr/local/bin/brew --version`
+    if [ -x "${WORKING_DIR}/bin/brew" ]; then 
+        echo "Found brew installation with version" ` brew --version`
         echo "Installing ruby version to brew" $RUBY_VERSION
         brew install ruby@$RUBY_VERSION
     else
@@ -32,6 +50,6 @@ echo "Adding $RUBY_PATH to the path before the install"
 export PATH=$RUBY_PATH:$PATH
 
 echo "Installing cocoapods"
-/usr/local/opt/ruby@$RUBY_VERSION/bin/gem install --no-document --user-install cocoapods -v $COCOAPODS_VERSION
+${WORKING_DIR}/opt/ruby@$RUBY_VERSION/bin/gem install --no-document --user-install cocoapods -v $COCOAPODS_VERSION
 
 source setup/setup_shared_native.sh