Rename GWP-ASan android_mallopt() arguments

The previous names were difficult to decipher. Now, let's change this
all to be more clear as it's actually one android_mallopt() call
depending on where it's called from, rather than the intended behaviour.

Also updated the comments so it's clear what happened across different
versions of Android.

Test: atest bionic-unit-tests CtsGwpAsanTestCases
Bug: N/a
Change-Id: I0582cab0b74aa09f4af54f9fbe5ba22697f82082
diff --git a/libc/bionic/gwp_asan_wrappers.cpp b/libc/bionic/gwp_asan_wrappers.cpp
index 11f7ced..2124f51 100644
--- a/libc/bionic/gwp_asan_wrappers.cpp
+++ b/libc/bionic/gwp_asan_wrappers.cpp
@@ -57,7 +57,7 @@
 static gwp_asan::GuardedPoolAllocator GuardedAlloc;
 static const MallocDispatch* prev_dispatch;
 
-using Action = android_mallopt_gwp_asan_options_t::Action;
+using Mode = android_mallopt_gwp_asan_options_t::Mode;
 using Options = gwp_asan::options::Options;
 
 // basename() is a mess, see the manpage. Let's be explicit what handling we
@@ -261,8 +261,8 @@
   options->Recoverable = true;
   GwpAsanRecoverable = true;
 
-  if (mallopt_options.desire == Action::TURN_ON_WITH_SAMPLING ||
-      mallopt_options.desire == Action::TURN_ON_FOR_APP_SAMPLED_NON_CRASHING) {
+  if (mallopt_options.mode == Mode::SYSTEM_PROCESS_OR_SYSTEM_APP ||
+      mallopt_options.mode == Mode::APP_MANIFEST_DEFAULT) {
     *process_sample_rate = kDefaultProcessSampling;
   } else {
     *process_sample_rate = 1;
@@ -285,7 +285,7 @@
   // be used. Tests still continue to use the environment variable though.
   if (*basename != '\0') {
     const char* default_sysprop = system_sysprop;
-    if (mallopt_options.desire == Action::TURN_ON_FOR_APP) {
+    if (mallopt_options.mode == Mode::APP_MANIFEST_ALWAYS) {
       default_sysprop = app_sysprop;
     }
     async_safe_format_buffer(&program_specific_sysprop[0], kSyspropMaxLen, "%s%s",
@@ -425,7 +425,7 @@
   Options options;
   unsigned process_sample_rate = kDefaultProcessSampling;
   if (!GetGwpAsanOptions(&options, &process_sample_rate, mallopt_options) &&
-      mallopt_options.desire == Action::DONT_TURN_ON_UNLESS_OVERRIDDEN) {
+      mallopt_options.mode == Mode::APP_MANIFEST_NEVER) {
     return false;
   }
 
@@ -492,7 +492,7 @@
 
   android_mallopt_gwp_asan_options_t mallopt_options;
   mallopt_options.program_name = progname;
-  mallopt_options.desire = Action::TURN_ON_WITH_SAMPLING;
+  mallopt_options.mode = Mode::SYSTEM_PROCESS_OR_SYSTEM_APP;
 
   return MaybeInitGwpAsan(globals, mallopt_options);
 }