Infer CPUs for tvOS and watchOS when on Apple Silicon

This PR contains the same logical change as aaae8ce but for watchOS and tvOS. When on Apple Silicon, we should build for the right CPU architecture. This is `sim_arm64` for tvOS and `arm64` for watchOS.

On a separate note, I'm not sure if `i386` should be the default architecture for watchOS anymore. I'm happy to change that to `x86_64` to align with all the other platforms if people agree.

Closes #16547.

PiperOrigin-RevId: 483997916
Change-Id: I67b7f2e2edac5184787f3c3511dc49bb4aeef108

src/main/java/com/google/devtools/build/lib/rules/apple/AppleCommandLineOptions.java

@@ -193,10 +193,12 @@ public class AppleCommandLineOptions extends FragmentOptions {
   @VisibleForTesting static final String DEFAULT_IOS_CPU = "x86_64";
 
   /** The default watchos CPU value. */
-  public static final String DEFAULT_WATCHOS_CPU = "i386";
+  public static final String DEFAULT_WATCHOS_CPU =
+      CPU.getCurrent() == CPU.AARCH64 ? "arm64" : "i386";
 
   /** The default tvOS CPU value. */
-  public static final String DEFAULT_TVOS_CPU = "x86_64";
+  public static final String DEFAULT_TVOS_CPU =
+      CPU.getCurrent() == CPU.AARCH64 ? "sim_arm64" : "x86_64";
 
   /** The default macOS CPU value. */
   public static final String DEFAULT_MACOS_CPU =