Makefile: move NDK_ROOT below ANDROID_HOME detection

If ANDROID_HOME is being detected by the code that finds a valid home
with an empty host environment, then NDK_ROOT should be able to use
that, but it was out of order in the evaluation.

Updates #cleanup

Signed-off-by: James Tucker <james@tailscale.com>

Makefile

@@ -13,19 +13,6 @@
 DOCKER_IMAGE := tailscale-android-build-amd64-041425-1
 export TS_USE_TOOLCHAIN=1
 
-# Auto-select an NDK from ANDROID_HOME (choose highest version available)
-NDK_ROOT ?= $(shell ls -1d $(ANDROID_HOME)/ndk/* 2>/dev/null | sort -V | tail -n 1)
-
-HOST_OS := $(shell uname | tr A-Z a-z)
-ifeq ($(HOST_OS),linux)
-    STRIP_TOOL := $(NDK_ROOT)/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-objcopy
-else ifeq ($(HOST_OS),darwin)
-    STRIP_TOOL := $(NDK_ROOT)/toolchains/llvm/prebuilt/darwin-x86_64/bin/llvm-objcopy
-endif
-
-$(info Using NDK_ROOT: $(NDK_ROOT))
-$(info Using STRIP_TOOL: $(STRIP_TOOL))
-
 DEBUG_APK := tailscale-debug.apk
 RELEASE_AAB := tailscale-release.aab
 RELEASE_TV_AAB := tailscale-tv-release.aab
@@ -64,6 +51,21 @@ ifeq ($(ANDROID_SDK_ROOT),)
 endif
 export ANDROID_HOME ?= $(ANDROID_SDK_ROOT)
 
+# Auto-select an NDK from ANDROID_HOME (choose highest version available)
+NDK_ROOT ?= $(shell ls -1d $(ANDROID_HOME)/ndk/* 2>/dev/null | sort -V | tail -n 1)
+
+HOST_OS := $(shell uname | tr A-Z a-z)
+ifeq ($(HOST_OS),linux)
+    STRIP_TOOL := $(NDK_ROOT)/toolchains/llvm/prebuilt/linux-x86_64/bin/llvm-objcopy
+else ifeq ($(HOST_OS),darwin)
+    STRIP_TOOL := $(NDK_ROOT)/toolchains/llvm/prebuilt/darwin-x86_64/bin/llvm-objcopy
+endif
+
+$(info Using ANDROID_HOME: $(ANDROID_HOME))
+$(info Using NDK_ROOT: $(NDK_ROOT))
+$(info Using STRIP_TOOL: $(STRIP_TOOL))
+
+
 # Attempt to find Android Studio for Linux configuration, which does not have a
 # predetermined location.
 ANDROID_STUDIO_ROOT ?= $(shell find ~/android-studio /usr/local/android-studio /opt/android-studio /Applications/Android\ Studio.app $(PROGRAMFILES)/Android/Android\ Studio -type d -maxdepth 1 2>/dev/null | head -n 1)