android sdk tools: adapt path to file hierarchy changes

Recent Android SDK tools, including e.g. "8092744" and "8512546" [1][2],
use a different path structure than e.g. "6514223" [0].
E.g. `sdkmanager` in older sdk tools used to be located at
  ${ANDROID_SDK_HOME}/tools/bin/sdkmanager
but now it is at
  ${ANDROID_SDK_HOME}/cmdline-tools/bin/sdkmanager

[0]: https://dl.google.com/android/repository/commandlinetools-linux-6514223_latest.zip
[1]: https://dl.google.com/android/repository/commandlinetools-linux-8092744_latest.zip
[2]: https://dl.google.com/android/repository/commandlinetools-linux-8512546_latest.zip

Related:
kivy#2540
kivy#2593

Author: SomberNight

pythonforandroid/build.py

@@ -73,7 +73,10 @@ def get_toolchain_versions(ndk_dir, arch):
 
 
 def get_targets(sdk_dir):
-    if exists(join(sdk_dir, 'tools', 'bin', 'avdmanager')):
+    if exists(join(sdk_dir, 'cmdline-tools', 'bin', 'avdmanager')):
+        avdmanager = sh.Command(join(sdk_dir, 'cmdline-tools', 'bin', 'avdmanager'))
+        targets = avdmanager('list', 'target').stdout.decode('utf-8').split('\n')
+    elif exists(join(sdk_dir, 'tools', 'bin', 'avdmanager')):
         avdmanager = sh.Command(join(sdk_dir, 'tools', 'bin', 'avdmanager'))
         targets = avdmanager('list', 'target').stdout.decode('utf-8').split('\n')
     elif exists(join(sdk_dir, 'tools', 'android')):