Add an env variable for the tzdata module root

The ANDROID_TZDATA_ROOT maps to the /apex/com.android.tzdata
location on device like ANDROID_RUNTIME_ROOT maps to the
/apex/com.android.runtime location.

Bug: 128422035
Test: build only
Change-Id: Id90006004ca652564e530f3694600ac4afd798ed
diff --git a/rootdir/init.environ.rc.in b/rootdir/init.environ.rc.in
index 5d6cd2d..455c9a8 100644
--- a/rootdir/init.environ.rc.in
+++ b/rootdir/init.environ.rc.in
@@ -6,6 +6,7 @@
     export ANDROID_DATA /data
     export ANDROID_STORAGE /storage
     export ANDROID_RUNTIME_ROOT /apex/com.android.runtime
+    export ANDROID_TZDATA_ROOT /apex/com.android.tzdata
     export EXTERNAL_STORAGE /sdcard
     export ASEC_MOUNTPOINT /mnt/asec
     export BOOTCLASSPATH %BOOTCLASSPATH%