[ndk] Change android ndk root for v8

Because of the android sdk managed by CIPD (see go/use-adjective-apis),
its deps repo ndk needs to be relocated to third_party/android_ndk.
This CL changes the ndk root path in files in v8.

Bug: chromium:659808
Change-Id: I78d534cbb81eebd1dc631293d54764f027ed0567
Reviewed-on: https://chromium-review.googlesource.com/861182Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50493}

build_overrides/build.gni

@@ -8,7 +8,7 @@ build_with_chromium = false
 
 # Uncomment these to specify a different NDK location and version in
 # non-Chromium builds.
-# default_android_ndk_root = "//third_party/android_tools/ndk"
+# default_android_ndk_root = "//third_party/android_ndk"
 # default_android_ndk_version = "r10e"
 
 # Some non-Chromium builds don't support building java targets.

gypfiles/standalone.gypi

@@ -296,7 +296,7 @@
           'variables': {
             # The Android toolchain needs to use the absolute path to the NDK
             # because it is used at different levels in the GYP files.
-            'android_ndk_root%': '<(base_dir)/third_party/android_tools/ndk/',
+            'android_ndk_root%': '<(base_dir)/third_party/android_ndk/',
             'android_host_arch%': "<!(uname -m | sed -e 's/i[3456]86/x86/')",
             # Version of the NDK. Used to ensure full rebuilds on NDK rolls.
             'android_ndk_version%': 'r12b',