Add python3-tk into the BASE_REQUIRED_PKGS list.

Bug: 158876253
Test: sudo apt-get remove python3-tk
      acloud-dev setup --host --force
Change-Id: Ie0518a472850aeb11f4a5e9f16df6ff46190a825
diff --git a/setup/host_setup_runner.py b/setup/host_setup_runner.py
index 9a668e5..c2bb8e8 100644
--- a/setup/host_setup_runner.py
+++ b/setup/host_setup_runner.py
@@ -39,7 +39,7 @@
 # Packages "devscripts" and "equivs" are required for "mk-build-deps".
 _AVD_REQUIRED_PKGS = [
     "devscripts", "equivs", "libvirt-clients", "libvirt-daemon-system"]
-_BASE_REQUIRED_PKGS = ["ssvnc", "lzop"]
+_BASE_REQUIRED_PKGS = ["ssvnc", "lzop", "python3-tk"]
 _CUTTLEFISH_COMMOM_PKG = "cuttlefish-common"
 _CF_COMMOM_FOLDER = "cf-common"
 _LIST_OF_MODULES = ["kvm_intel", "kvm"]