Update IntelliSense modes to correct architecture (#3713)

VS Code is saying IntelliSense mode doesn't match what it probes.

Update the IntelliSense modes to use the right compiler & architecture.

I have no idea what this actually affects.

.vscode/c_cpp_properties.json

@@ -40,7 +40,7 @@
             "name": "Android x64 debug (GN)",
             "cStandard": "c11",
             "cppStandard": "c++11",
-            "intelliSenseMode": "gcc-x64",
+            "intelliSenseMode": "clang-x64",
             "compileCommands": "${workspaceFolder}/out/debug/compile_commands.android_x64.json",
             "compilerPath": "/opt/android/android-ndk-r21b/toolchains/llvm/prebuilt/linux-x86_64/bin/x86_64-linux-android24-clang",
             "browse": {
@@ -52,7 +52,7 @@
             "name": "Android arm64 debug (GN)",
             "cStandard": "c11",
             "cppStandard": "c++11",
-            "intelliSenseMode": "gcc-x64",
+            "intelliSenseMode": "clang-arm64",
             "compileCommands": "${workspaceFolder}/out/debug/compile_commands.android_arm64.json",
             "compilerPath": "/opt/android/android-ndk-r21b/toolchains/llvm/prebuilt/linux-x86_64/bin/aarch64-linux-android24-clang",
             "browse": {
@@ -64,7 +64,7 @@
             "name": "EFR32 examples debug (GN)",
             "cStandard": "c11",
             "cppStandard": "c++11",
-            "intelliSenseMode": "gcc-x64",
+            "intelliSenseMode": "gcc-arm",
             "compileCommands": "${workspaceFolder}/out/debug/compile_commands.efr32.json",
             "compilerPath": "/opt/ARM-software/gcc-arm-none-eabi-9-2019-q4-major/bin/arm-none-eabi-gcc",
             "browse": {