[Chromecast] Use symbol_level=1 for 32-bit GCC toolchains.

build/config/android/config.gni

Index: build/config/android/config.gni
diff --git a/build/config/android/config.gni b/build/config/android/config.gni
index d5948f2fbf373c0b89c3074d912d5b821ffaa450..d335c991664284df0090d8f99eff8ddf9dab7f10 100644
--- a/build/config/android/config.gni
+++ b/build/config/android/config.gni
@@ -309,6 +309,12 @@ if (is_android) {
   }
 
   # Secondary ABI -------------------------------------------------------------
+  # android_64bit_target_cpu has been deprecated and will soon be removed. Use
+  # is_target_cpu_64bit instead (see //build/config/compiler/compiler.gni).
+  # Note: This variable cannot take the value of is_target_cpu_64bit directly,
+  # as that would cause an import loop.
+  # TODO(agrieve): Remove this variable once it's no longer used downstream.
+  # https://crbug.com/671624
   if (target_cpu == "arm64" || target_cpu == "x64" || target_cpu == "mips64el") {
     android_64bit_target_cpu = true
   } else if (target_cpu == "arm" || target_cpu == "x86" ||