hostIntf: unload all external apps before erasing the shared area

Test: Load nanoapp with recuring timer. Load enough additional nanoapps
to trigger flash erase. Confirm system doesn't hard fault when calling
the timer callback after the shared area is erased.
Bug: 32000008
Bug: 30945807
Change-Id: I997fa784024dba94cf2c87a917bb7dce89593d92
Signed-off-by: Ben Fennema <fennema@google.com>
1 file changed