Revert "Increase android32_ndk_api_level 16 -> 21"

This reverts commit 1d5cb6af5192be1b701b389024e7c0121e8f2a7d.

Reason for revert: Breaking v8 kitkat bots

Original change's description:
> Increase android32_ndk_api_level 16 -> 21
>
> We only support 21+, so we should build for it.
>
> Bug: 1116198
> Change-Id: I552a946b245de0f54485ea985e08b53b92186bb1
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2367984
> Reviewed-by: Ben Mason <benmason@chromium.org>
> Commit-Queue: Ben Mason <benmason@chromium.org>
> Auto-Submit: Andrew Grieve <agrieve@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#804976}

TBR=agrieve@chromium.org,benmason@chromium.org

# Not skipping CQ checks because original CL landed > 1 day ago.

Bug: 1116198, 1126469
Change-Id: Ia59936b975b6a17ec102fea02b9e86ba15de7b7c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2401268
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#805510}
GitOrigin-RevId: 35c44df96c33dfd83a58d1d0683f30929e16c267

config/android/config.gni

@@ -49,6 +49,12 @@ if (is_android || is_chromeos) {
     # not explicitly set it.
     default_min_sdk_version = 21
 
+    # Android API level for 32 bits platforms
+    android32_ndk_api_level = 16
+
+    # Android API level for 64 bits platforms
+    android64_ndk_api_level = 21
+
     # [WIP] Allows devs to achieve much faster edit-build-install cycles.
     # Currently only works for ChromeModern apks due to incremental install.
     # This needs to be in a separate declare_args as it determines some of the
@@ -56,18 +62,6 @@ if (is_android || is_chromeos) {
     android_fast_local_dev = false
   }
 
-  declare_args() {
-    # Android API level for 32 bits platforms
-    android32_ndk_api_level = default_min_sdk_version
-
-    # Android API level for 64 bits platforms
-    if (default_min_sdk_version < 21) {
-      android64_ndk_api_level = 21
-    } else {
-      android64_ndk_api_level = default_min_sdk_version
-    }
-  }
-
   if (enable_chrome_android_internal) {
     import("//clank/config.gni")
   } else {