doc: improve building doc for Android

MeowShe · danielleadams · commit 97df9b84a2e1 · 2022-10-11T09:10:14.000-04:00
PR-URL: #44888 Refs: #44207 Reviewed-By: Feng Yu <F3n67u@outlook.com> Reviewed-By: James M Snell <jasnell@gmail.com>
diff --git a/BUILDING.md b/BUILDING.md
@@ -660,7 +660,7 @@ Be sure you have downloaded and extracted
 a folder. Then run:
 
 ```console
-$ source ./android-configure /path/to/your/android-ndk target_arch android_sdk_version
+$ ./android-configure <path to the Android NDK> <Android SDK version> <target architecture>
 $ make -j4
 ```
 
