android: [NewPM] Move ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER into llvm/

android: [NewPM] Move ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER into llvm/

Porting of commit
a36bd4c90dcc ("[CMake][NewPM] Move ENABLE_EXPERIMENTAL_NEW_PASS_MANAGER into llvm/")

Fixes the following building error:

In file included from external/llvm-project/llvm/lib/LTO/LTOBackend.cpp:16:
In file included from external/llvm-project/llvm/include/llvm/LTO/LTOBackend.h:22:
In file included from external/llvm-project/llvm/include/llvm/LTO/LTO.h:22:
external/llvm-project/llvm/include/llvm/LTO/Config.h:57:19: error: use of undeclared identifier 'LLVM_ENABLE_NEW_PASS_MANAGER'
  bool UseNewPM = LLVM_ENABLE_NEW_PASS_MANAGER;
                  ^
1 error generated.