android: envsetup.sh: Unconditionally set ANDROID_SDK_ROOT.

This was used long ago for testing with custom SDKs.  Nowadays, most
SDK references are inside a .gn file, and this script here only adds
platform-tools/ and tools/ from the SDK to PATH.  People can just
set PATH to their custom SDK if they want.

Bug: 330631
Change-Id: I1a88c0f18289b418c2299523b7f6a0099d660233
Reviewed-on: https://chromium-review.googlesource.com/579951Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#488284}

build/android/envsetup.sh

@@ -33,12 +33,7 @@ android_envsetup_main() {
     echo "${CHROME_SRC}"
   fi
 
-  # Allow the caller to override a few environment variables. If any of them is
-  # unset, we default to a sane value that's known to work. This allows for
-  # experimentation with a custom SDK.
-  if [[ -z "${ANDROID_SDK_ROOT}" || ! -d "${ANDROID_SDK_ROOT}" ]]; then
-    local ANDROID_SDK_ROOT="${CHROME_SRC}/third_party/android_tools/sdk/"
-  fi
+  local ANDROID_SDK_ROOT="${CHROME_SRC}/third_party/android_tools/sdk/"
 
   # Add Android SDK tools to system path.
   export PATH=$PATH:${ANDROID_SDK_ROOT}/platform-tools