libbinder: remove __ANDROID_APEX__ stability diff

These were setup because the media APEX module was using vendor variants
of libbinder on the system partition. However, now that this build
dependency is cleaned up, we can remove the #ifdefs and make this a
build error instead of a runtime error.

Test: binderStabilityTest
Fixes: 179906909
Change-Id: If05cf3fa0851866d7113f6e8f9705891672ad369
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index 1a4ede1..3773760 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -520,7 +520,7 @@
     }
 }
 
-#if defined(__ANDROID_VNDK__) && !defined(__ANDROID_APEX__)
+#if defined(__ANDROID_VNDK__)
 constexpr int32_t kHeader = B_PACK_CHARS('V', 'N', 'D', 'R');
 #else
 constexpr int32_t kHeader = B_PACK_CHARS('S', 'Y', 'S', 'T');
diff --git a/libs/binder/ProcessState.cpp b/libs/binder/ProcessState.cpp
index c38249e..edadcd5 100644
--- a/libs/binder/ProcessState.cpp
+++ b/libs/binder/ProcessState.cpp
@@ -406,12 +406,6 @@
     , mThreadPoolSeq(1)
     , mCallRestriction(CallRestriction::NONE)
 {
-
-// TODO(b/166468760): enforce in build system
-#if defined(__ANDROID_APEX__)
-    LOG_ALWAYS_FATAL("Cannot use libbinder in APEX (only system.img libbinder) since it is not stable.");
-#endif
-
     if (mDriverFD >= 0) {
         // mmap the binder, providing a chunk of virtual address space to receive transactions.
         mVMStart = mmap(nullptr, BINDER_VM_SIZE, PROT_READ, MAP_PRIVATE | MAP_NORESERVE, mDriverFD, 0);
diff --git a/libs/binder/Stability.cpp b/libs/binder/Stability.cpp
index 339c538..b56e09f 100644
--- a/libs/binder/Stability.cpp
+++ b/libs/binder/Stability.cpp
@@ -76,18 +76,12 @@
 }
 
 Stability::Level Stability::getLocalLevel() {
+#ifdef __ANDROID_APEX__
+#error APEX can't use libbinder (must use libbinder_ndk)
+#endif
+
 #ifdef __ANDROID_VNDK__
-    #ifdef __ANDROID_APEX__
-        // TODO(b/142684679) avoid use_vendor on system APEXes
-        #if !defined(__ANDROID_APEX_COM_ANDROID_MEDIA_SWCODEC__) \
-            && !defined(__ANDROID_APEX_TEST_COM_ANDROID_MEDIA_SWCODEC__)
-        #error VNDK + APEX only defined for com.android.media.swcodec
-        #endif
-        // TODO(b/142684679) avoid use_vendor on system APEXes
-        return Level::SYSTEM;
-    #else
-        return Level::VENDOR;
-    #endif
+    return Level::VENDOR;
 #else
     // TODO(b/139325195): split up stability levels for system/APEX.
     return Level::SYSTEM;
diff --git a/libs/binder/ndk/include_platform/android/binder_stability.h b/libs/binder/ndk/include_platform/android/binder_stability.h
index f5e8bf6..7a2d2b8 100644
--- a/libs/binder/ndk/include_platform/android/binder_stability.h
+++ b/libs/binder/ndk/include_platform/android/binder_stability.h
@@ -30,7 +30,7 @@
     FLAG_PRIVATE_VENDOR = 0x10000000,
 };
 
-#if defined(__ANDROID_VNDK__) && !defined(__ANDROID_APEX__)
+#if defined(__ANDROID_VNDK__)
 
 enum {
     FLAG_PRIVATE_LOCAL = FLAG_PRIVATE_VENDOR,
@@ -45,7 +45,7 @@
     AIBinder_markVendorStability(binder);
 }
 
-#else  // defined(__ANDROID_VNDK__) && !defined(__ANDROID_APEX__)
+#else  // defined(__ANDROID_VNDK__)
 
 enum {
     FLAG_PRIVATE_LOCAL = 0,
@@ -62,7 +62,7 @@
     AIBinder_markSystemStability(binder);
 }
 
-#endif  // defined(__ANDROID_VNDK__) && !defined(__ANDROID_APEX__)
+#endif  // defined(__ANDROID_VNDK__)
 
 /**
  * This interface has system<->vendor stability