hg: jdk7u/jdk7u/jdk: 8260356: (tz) Upgrade time-zone data to tzdata2021a

[dcherepanov]

Changeset: 898cb597862f
Author:    dcherepanov
Date:      2021-03-22 06:11 +0000
URL:       https://hg.openjdk.java.net/jdk7u/jdk7u/jdk/rev/898cb597862f

8260356: (tz) Upgrade time-zone data to tzdata2021a
Reviewed-by: bae

! make/sun/javazic/tzdata/VERSION
! make/sun/javazic/tzdata/africa
! make/sun/javazic/tzdata/leapseconds