Strip my_shared_libraries to remove space char

This commit strips my_shared_libraries to remove the unwanted space
character when both `$(filter-out ...)` and
`$(my_system_shared_libraries)` are empty.

Bug: 137302468
Test: lunch aosp_walleye-userdebug && make
Test: lunch aosp_walleye-userdebug && make check-elf-files
Change-Id: Ia0410da877196c104a61d48c92a2be969a9754a5
diff --git a/core/cc_prebuilt_internal.mk b/core/cc_prebuilt_internal.mk
index c0e45b2..0c87151 100644
--- a/core/cc_prebuilt_internal.mk
+++ b/core/cc_prebuilt_internal.mk
@@ -135,9 +135,9 @@
     endif
 endif
 
-my_shared_libraries := \
+my_shared_libraries := $(strip \
     $(filter-out $(my_system_shared_libraries),$(LOCAL_SHARED_LIBRARIES)) \
-    $(my_system_shared_libraries)
+    $(my_system_shared_libraries))
 
 # Extra shared libraries introduced by LOCAL_CXX_STL (may append some libraries to
 # my_shared_libraries).