Prevent getLegacyCxxModule from being stripped

Summary: `ReactPackageTurboModuleManagerDelegate.getLegacyCxxModule` isn't called from Java. Therefore, ProGuard will strip this method to reduce code size. To prevent this, we need to add the `DoNotStrip` annotation to this method. This annotation isn't necessary for the `getModule` method, since `getModule` is used in `TurboModuleManager.getJavaModule`.

Reviewed By: fkgozali

Differential Revision: D15996432

fbshipit-source-id: d34a7d28f7678e2dfc917f52d5cacc286bc33a0a

ReactAndroid/src/main/java/com/facebook/react/turbomodule/core/BUCK

@@ -13,6 +13,7 @@ rn_android_library(
         "PUBLIC",
     ],
     deps = [
+        react_native_dep("java/com/facebook/proguard/annotations:annotations"),
         react_native_dep("java/com/facebook/systrace:systrace"),
         react_native_dep("libraries/soloader/java/com/facebook/soloader:soloader"),
         react_native_dep("third-party/java/infer-annotations:infer-annotations"),

ReactAndroid/src/main/java/com/facebook/react/turbomodule/core/ReactPackageTurboModuleManagerDelegate.java

@@ -3,6 +3,7 @@
 package com.facebook.react.turbomodule.core;
 
 import com.facebook.infer.annotation.Assertions;
+import com.facebook.proguard.annotations.DoNotStrip;
 import com.facebook.react.ReactPackage;
 import com.facebook.react.TurboReactPackage;
 import com.facebook.react.bridge.CxxModuleWrapper;
@@ -32,6 +33,7 @@ public abstract class ReactPackageTurboModuleManagerDelegate extends TurboModule
 
   @Nullable
   @Override
+  @DoNotStrip
   public TurboModule getModule(String moduleName) {
     TurboModule module = resolveModule(moduleName);
     if (module == null) {