Adopt the new prebuilts/ndk/<number> paths.

Bug: 6932421
Change-Id: Iba7200aacef2201001f92c6ffa020881f0b528ea
diff --git a/core/binary.mk b/core/binary.mk
index 23bbc81..3f01489 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -24,8 +24,8 @@
   ifndef LOCAL_SDK_VERSION
     $(error $(LOCAL_PATH): LOCAL_NDK_VERSION must be defined with LOCAL_SDK_VERSION)
   endif
-  my_ndk_source_root := $(HISTORICAL_NDK_VERSIONS_ROOT)/android-ndk-r$(LOCAL_NDK_VERSION)/sources
-  my_ndk_version_root := $(HISTORICAL_NDK_VERSIONS_ROOT)/android-ndk-r$(LOCAL_NDK_VERSION)/platforms/android-$(LOCAL_SDK_VERSION)/arch-$(TARGET_ARCH)
+  my_ndk_source_root := $(HISTORICAL_NDK_VERSIONS_ROOT)/$(LOCAL_NDK_VERSION)/sources
+  my_ndk_version_root := $(HISTORICAL_NDK_VERSIONS_ROOT)/$(LOCAL_NDK_VERSION)/platforms/android-$(LOCAL_SDK_VERSION)/arch-$(TARGET_ARCH)
   ifeq ($(wildcard $(my_ndk_version_root)),)
     $(error $(LOCAL_PATH): ndk version root does not exist: $(my_ndk_version_root))
   endif
diff --git a/core/config.mk b/core/config.mk
index 194fbe1..8be9457 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -323,13 +323,6 @@
 COLUMN:= column
 endif
 
-dir := $(shell uname)
-ifeq ($(HOST_OS),windows)
-dir := $(HOST_OS)
-endif
-ifeq ($(HOST_OS),darwin)
-dir := $(HOST_OS)-$(HOST_ARCH)
-endif
 OLD_FLEX := prebuilts/misc/$(HOST_PREBUILT_TAG)/flex/flex-2.5.4a$(HOST_EXECUTABLE_SUFFIX)
 
 ifeq ($(HOST_OS),darwin)
@@ -441,8 +434,8 @@
     $(wildcard $(HISTORICAL_SDK_VERSIONS_ROOT)/*/android.jar)))
 
 TARGET_AVAILABLE_NDK_VERSIONS := $(call numerically_sort,\
-    $(patsubst $(HISTORICAL_NDK_VERSIONS_ROOT)/android-ndk-r%,%, \
-    $(wildcard $(HISTORICAL_NDK_VERSIONS_ROOT)/android-ndk-r*)))
+    $(patsubst $(HISTORICAL_NDK_VERSIONS_ROOT)/%/platforms,%, \
+    $(wildcard $(HISTORICAL_NDK_VERSIONS_ROOT)/*/platforms)))
 
 INTERNAL_PLATFORM_API_FILE := $(TARGET_OUT_COMMON_INTERMEDIATES)/PACKAGING/public_api.txt
 
diff --git a/core/package.mk b/core/package.mk
index 3f911fb..50b9f7a 100644
--- a/core/package.mk
+++ b/core/package.mk
@@ -312,7 +312,7 @@
     LOCAL_PACKAGE_NAME=$(LOCAL_PACKAGE_NAME))
 endif
 jni_shared_libraries += \
-    $(HISTORICAL_NDK_VERSIONS_ROOT)/android-ndk-r$(LOCAL_NDK_VERSION)/sources/cxx-stl/stlport/libs/$(TARGET_CPU_ABI)/libstlport_shared.so
+    $(HISTORICAL_NDK_VERSIONS_ROOT)/$(LOCAL_NDK_VERSION)/sources/cxx-stl/stlport/libs/$(TARGET_CPU_ABI)/libstlport_shared.so
 endif
 
 # Set the abi directory used by the local JNI shared libraries.