Change isolated storage to be targeting future API level 29

The way that future API level is calculated is the reported
API level, and plus one if it's not a released platform;
therefore isolated storage should be targeting 29 not 28.

Bug: 131937957
Test: None

Change-Id: I82d0c3f3e83094d0b314b38bd7161d2fcf7afbb0
(cherry picked from commit 72c5a2fe6da2da99532eddb13c814b3def637499)
2 files changed