Link statically stdlibc++ for android builds

build/config/compiler/BUILD.gn

@@ -92,7 +92,14 @@ config("abi_default") {
       ]
     }
   }
+
   ldflags = cflags
+
+  if (current_os == "android") {
+    ldflags += [
+      "-static-libstdc++",
+    ]
+  }
 }
 
 config("target_default") {

src/android/CHIPTool/README.md

@@ -58,14 +58,4 @@ rsync -a out/android_arm64/lib/jni/* src/android/CHIPTool/app/src/main/jniLibs
     ## JAR and .so libraries will be copy to target directories.
     ```
 
-6. You will also need the "libc++\_shared.so" file in the jniLibs folder. This
-   file comes packaged with Android NDK and can be found under
-   `$ANDROID_NDK_HOME/sources/cxx-stl/llvm-libc++/libs/$TARGET`, e.g.
-
-    `rsync -a "${ANDROID_NDK_HOME}/sources/cxx-stl/llvm-libc++/libs/arm64-v8a/libc++_shared.so" src/android/CHIPTool/app/src/main/jniLibs/arm64-v8a/`
-
-    (Eventually hoping to not have to include this .so, but that needs some more
-    tweaking of the Android automake build rules. Include it in the interim to
-    be able to build the Android app).
-
-7. 'Gradle sync' the Android project and run.
+6. 'Gradle sync' the Android project and run.