Fix dump-tzdata.sh for "zic -b slim" files am: de11b51fbc am: 907cad017c am: cc3fbd1d1e

Original change: https://android-review.googlesource.com/c/platform/system/timezone/+/1454836

Change-Id: Ia03f62f4d289ee6cf876e9958bf50b2711d98d3f