Android: Remove unwind asset from Monochrome6432

As per discussion with ssid@, 64-bit browser builds should not have a
32-bit unwind asset in them.

R=estevenson

Bug: 1038962
Change-Id: I012138cff1071d74f2722277a90758d44bf8677b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1993676
Auto-Submit: Christopher Grant <cjgrant@chromium.org>
Reviewed-by: Eric Stevenson <estevenson@chromium.org>
Commit-Queue: Christopher Grant <cjgrant@chromium.org>
Cr-Commit-Position: refs/heads/master@{#729978}

chrome/android/chrome_public_apk_tmpl.gni

@@ -86,7 +86,8 @@ template("chrome_public_common_apk_or_module_tmpl") {
     _add_unwind_tables = invoker.add_unwind_tables_in_apk
   } else {
     _needs_32bit_lib =
-        target_cpu == "arm" || (_is_monochrome && target_cpu == "arm64")
+        target_cpu == "arm" ||
+        (_is_monochrome && target_cpu == "arm64" && !_is_64_bit_browser)
     _add_unwind_tables =
         _needs_32bit_lib && _add_unwind_tables_in_chrome_32bit_apk &&
         ((android_64bit_target_cpu &&