Revert "Change symlink_forest to use relative symlinks."

Revert submission 2673616-relativesymlinks-fix

Reason for revert: this breaks tests verified with go/abtd https://android-build.googleplex.com/builds/abtd/run/L36000000963001181

Bug: 300122962

Reverted changes: /q/submissionid:2673616-relativesymlinks-fix

Change-Id: I5a97c4fbe4df5727c0604a07137093d0f00c7776

tests/lib.sh

@@ -8,15 +8,10 @@ HARDWIRED_MOCK_TOP=
 
 REAL_TOP="$(readlink -f "$(dirname "$0")"/../../..)"
 
-function make_mock_top {
-  mock=$(mktemp -t -d st.XXXXX)
-  echo "$mock"
-}
-
 if [[ -n "$HARDWIRED_MOCK_TOP" ]]; then
   MOCK_TOP="$HARDWIRED_MOCK_TOP"
 else
-  MOCK_TOP=$(make_mock_top)
+  MOCK_TOP=$(mktemp -t -d st.XXXXX)
   trap cleanup_mock_top EXIT
 fi
 
@@ -202,10 +197,3 @@ function scan_and_run_tests {
     info "Completed test case \e[96;1m$f\e[0m"
   done
 }
-
-function move_mock_top {
-  MOCK_TOP2=$(make_mock_top)
-  mv $MOCK_TOP $MOCK_TOP2
-  MOCK_TOP=$MOCK_TOP2
-  trap cleanup_mock_top EXIT
-}