android(toolchain): fix find_path() behavior (zlib search problem)

platforms/android/android.toolchain.cmake

@@ -1587,7 +1587,13 @@ set( ANDROID True )
 set( BUILD_ANDROID True )
 
 # where is the target environment
-set( CMAKE_FIND_ROOT_PATH "${ANDROID_TOOLCHAIN_ROOT}/bin" "${ANDROID_TOOLCHAIN_ROOT}/${ANDROID_TOOLCHAIN_MACHINE_NAME}" "${ANDROID_SYSROOT}" "${CMAKE_INSTALL_PREFIX}" "${CMAKE_INSTALL_PREFIX}/share" )
+set( CMAKE_FIND_ROOT_PATH
+    "${ANDROID_TOOLCHAIN_ROOT}/bin"
+    "${ANDROID_TOOLCHAIN_ROOT}/${ANDROID_TOOLCHAIN_MACHINE_NAME}"
+    "${ANDROID_SYSROOT}"
+    "${ANDROID_NDK}/sysroot"  # NDK16+
+    "${CMAKE_INSTALL_PREFIX}"
+    "${CMAKE_INSTALL_PREFIX}/share" )
 
 # only search for libraries and includes in the ndk toolchain
 set( CMAKE_FIND_ROOT_PATH_MODE_PROGRAM ONLY )