setup.sh improvements (#2858)

Summary:
Use cmake-out-android to avoid mess up with cmake-out
Fix comments

Pull Request resolved: #2858

Reviewed By: mergennachin

Differential Revision: D55778927

fbshipit-source-id: dc81c940dc765b8b437f8d40838c5ac4d203c2e7

Author: kirklandsign

examples/demo-apps/android/LlamaDemo/setup.sh

@@ -7,8 +7,8 @@
 
 set -eu
 
-CMAKE_OUT="${CMAKE_OUT:-cmake-out}"
-# Note: Set up ANDROID_NDK, ANDROID_ABI, BUCK2, and FLATC
+CMAKE_OUT="${CMAKE_OUT:-cmake-out-android}"
+# Note: Set up ANDROID_NDK and ANDROID_ABI
 cmake . -DCMAKE_INSTALL_PREFIX="${CMAKE_OUT}" \
   -DCMAKE_TOOLCHAIN_FILE="${ANDROID_NDK}/build/cmake/android.toolchain.cmake" \
   -DANDROID_ABI="${ANDROID_ABI}" \