Revert "Changed ANDROID_STL to use settings.compiler.libcxx"

This reverts commit 386c508.

conanfile.py

@@ -36,7 +36,7 @@ def configure(self):
  "but used %s" % (self.settings.arch, api_level))
  if self.settings.compiler.version != "8":
  raise ConanInvalidConfiguration("only Clang 8 is supported")
- if not str(self.settings.compiler.libcxx) in ["c++_shared", "c++_static"]:
+ if self.settings.compiler.libcxx != "libc++":
  raise ConanInvalidConfiguration("only libc++ standard library is supported")
 
  def source(self):
@@ -204,7 +204,7 @@ def package_info(self):
  self.env_info.ANDROID_PLATFORM = "android-%s" % self.settings.os.api_level
  self.env_info.ANDROID_TOOLCHAIN = "clang"
  self.env_info.ANDROID_ABI = self._android_abi
- self.env_info.ANDROID_STL = str(self.settings.compiler.libcxx)
+ self.env_info.ANDROID_STL = "c++_static"
 
  self.env_info.CMAKE_FIND_ROOT_PATH_MODE_PROGRAM = "BOTH"
  self.env_info.CMAKE_FIND_ROOT_PATH_MODE_LIBRARY = "BOTH"