Properly process CFlags featuring quotes and double quotes. Test: on libui and libgui Change-Id: I8581cef9ccc595b6e05d77bee7bea82f2efd219b
Test: Manually generated CMakeLists.txt for gui/ui/aapt2. Change-Id: I7dedc300c1e50b8e39bc58091b650c0bbe2c62da