drm_hwcomposer: CI: Keep nostdlibinc cflag option

Otherwise, the build will be broken due to the recent BIONIC [change][1].

[1]: https://android.googlesource.com/platform//bionic/+/47eb52732097ff9d4311f923ba48f4eabffe04b7%5E%21/#F0
Change-Id: I3d22cdfaa47ac037adb05442ef1b4f27da4505d5
Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>

.ci/Makefile

diff --git a/.ci/Makefile b/.ci/Makefile
index 051a437..7d3f086 100644
--- a/.ci/Makefile
+++ b/.ci/Makefile
@@ -16,8 +16,6 @@
 CXXARGS := $(subst [BASE_DIR],$(BASE_DIR),$(CXXARGS))
 # clang-tidy doesn't like -mcpu=xxx flag
 CXXARGS := $(patsubst -mcpu=%,,$(CXXARGS))
-# TODO: build aospless with gtest enabled and remove line below
-CXXARGS := $(subst -nostdlibinc,,$(CXXARGS))
 CXXARGS += -I. -I./tests/test_include $(CXXFLAGS)
 
 TIDY_FILES_OVERRIDE := \