Silence module path warnings for a while

Warning messages like, "libart_fake: framework library must be installed
to system/lib64 but requested to be installed at system/fake-libs64.
Please fix.", are temporarily muted since some of those warnings might
be false alarms.

Let's just silence the warning for everybody and investigate the cases
internally by turning on the build flag SHOW_MODULE_PATH_WARNINGS.

Test: the warning messages should not be shown unless built with
SHOW_MODULE_PATH_WARNINGS=true.

Change-Id: I5eb3ab3385c92a5192723ff1008277c321162191
diff --git a/core/base_rules.mk b/core/base_rules.mk
index 1fb516b..1763a06 100644
--- a/core/base_rules.mk
+++ b/core/base_rules.mk
@@ -299,10 +299,12 @@
     # paths.
     ifeq ($(my_module_is_soong),false)
       ifneq ($(my_module_path),$(my_module_default_path))
+        ifeq ($(SHOW_MODULE_PATH_WARNINGS),true)
         # TODO(b/35020635): s/warning/error/
         $(call pretty-warning,$(lib_type) library must be installed to \
 $(subst $(PRODUCT_OUT)/,,$(my_module_default_path)) but requested to be installed at \
 $(subst $(PRODUCT_OUT)/,,$(my_module_path)). Please fix.)
+        endif
       endif
     else
       # For Soong-defined module, symlink is provided if the path has been amended