[Android] Fix un-paired namespace declare for higher __ANDROID_API__

(cherry picked from commit b6f2d06996335c951bfb72f98b5b9e22dc9bc03e)

Bug: None
Test: Build with larger __ANDROID_API__ (29)
Change-Id: I5bfb8ad0ea5b866469191c5a385b071eec185716
Reviewed-on: https://chromium-review.googlesource.com/c/crashpad/crashpad/+/2522110
Reviewed-by: Joshua Peraza <[email protected]>
Commit-Queue: Robert Sesek <[email protected]>

third_party/crashpad/util/linux/initial_signal_dispositions.cc

@@ -20,9 +20,10 @@
 #include "base/logging.h"
 #include "build/build_config.h"
 
+namespace crashpad {
+
 #if __ANDROID_API__ <= 23
 
-namespace crashpad {
 namespace {
 bool LoggingSignal(int signum, sighandler_t handler) {
   sighandler_t previous = signal(signum, handler);