Fix invalid movie data crash

[cewert]

Ensure data is valid before using to prevent app crash. This comes from the roku.com crash log

Crashlog:

source           <uninitialized> 
json             Invali$1 m                roAssociativeArray refcnt=2 count:2 
global           Interface:ifGloba$1 Local Variables: 
   file/line: pkg:/components/data/MovieData.brs(8) 
#0  Function setfields() As Voi$1 Backtrace: 
'Dot' Operator attempted with invalid BrightScript Component or interface reference. (runtime error &hec) in pkg:/components/data/MovieData.brs(8)

Which points to this line after running build-prod on 2.0.8:

m.top.id = json.id

Changes

• validate data to prevent crash

Issues

Ref #1164