dump_modemlog: move all files to subdirectory

Since radioext has already moved to this folder, it doesn't make sense
for the base folder to be dump_modemlog. This change moves it to its
own subfolder so that we can also add more in the future.

Test: build and flash, trigger bugreport and check modem logs are there
Bug: 302435001
Change-Id: Ia83378074068526023f591d63b1e5ac4700b8103
diff --git a/modem/modem.mk b/modem/modem.mk
index 10df7d4..d921e74 100644
--- a/modem/modem.mk
+++ b/modem/modem.mk
@@ -1,5 +1 @@
-BOARD_VENDOR_SEPOLICY_DIRS += device/google/gs-common/modem/sepolicy
-
-PRODUCT_PACKAGES += dump_modem.sh
-PRODUCT_PACKAGES += dump_modemlog
-
+include device/google/gs-common/modem/dump_modemlog/dump_modemlog.mk