Rename fscrypt_is_native() to IsFbeEnabled()

Now that emulated FBE is no longer supported, there is no longer any
distinction between native FBE and emulated FBE.  There is just FBE.

Referring to FBE as "fscrypt" is also poor practice, as fscrypt (the
Linux kernel support for filesystem-level encryption) is just one part
of FBE, the Android feature.

Therefore, rename fscrypt_is_native() to IsFbeEnabled().

Bug: 232458753
Change-Id: Ib4dcdf799833b91d326b4b6f7120b0a3d4f4fc31
diff --git a/init/builtins.cpp b/init/builtins.cpp
index 9e1d93c..38f6f39 100644
--- a/init/builtins.cpp
+++ b/init/builtins.cpp
@@ -426,7 +426,7 @@
             return ErrnoError() << "fchmodat() failed on " << options.target;
         }
     }
-    if (fscrypt_is_native()) {
+    if (IsFbeEnabled()) {
         if (!FscryptSetDirectoryPolicy(ref_basename, options.fscrypt_action, options.target)) {
             return reboot_into_recovery(
                     {"--prompt_and_wipe_data", "--reason=set_policy_failed:"s + options.target});
@@ -1175,7 +1175,7 @@
     auto reboot = [reboot_reason, should_reboot_into_recovery](const std::string& message) {
         // TODO (b/122850122): support this in gsi
         if (should_reboot_into_recovery) {
-            if (fscrypt_is_native() && !android::gsi::IsGsiRunning()) {
+            if (IsFbeEnabled() && !android::gsi::IsGsiRunning()) {
                 LOG(ERROR) << message << ": Rebooting into recovery, reason: " << reboot_reason;
                 if (auto result = reboot_into_recovery(
                             {"--prompt_and_wipe_data", "--reason="s + reboot_reason});