Maulik has given you a good start. What you need to think about are the practical difference between the two options. The clear difference is "get". So what does "get + past participle" give us?
Well, firstly, movies don't release themselves! But I think you knew that. So our second option is not great, as we can't use "release" as an action of the movie itself. For this to work we would need a verb that can be something that a movie does.
If a movie doesn't suck.
Moving on to "get", in your first sentence; this sentence is perfect - it sounds natural and is entirely self-explanatory. "Get" is an extremely flexible verb with many uses and meanings. Its function in this case is to externalise the action. That is, we are saying that the action "occurred" without explaining how, and more importantly by who. This is a form of the passive/causative, which is a vital tool in English.
We use "get + past participle" to externalise an action where the "agent" (who did it) is unknown, unimportant, or self-explanatory.
Here are a couple of other examples:
When a book gets published, it is a nervy time for the author...
If you get arrested, it's important to know your rights...
In the event that you want to explain who performed this "externalised action", you can do so by simply using "by":
If a movie doesn't get released by a movie company, it's likely due to...
These two sentences are both in the passive voice, indicated by the passive(past) participle held. Both are passive voice, so this has no effect on our choice of sentence.
The first is being held is present continuous and the second is held is present simple. Here is a tutorial that explains the differences in usage for these two forms.
Present continuous is used for a situation which is temporary, or happens regularly before and after a given time, or is happening before and after the moment of speaking.
Present simple is used for things that are regularly, continually or are generally true.
Astronomical things change over immensely long timescales, so we talk about them as if they were generally true. The correct sentence therefore uses present simple:
The Earth is held by the gravity of the Sun and orbits around it.
Best Answer
I think the difference is primarily one of register. get asked is conversational whereas am asked is neutral.
to be asked
to get asked
get + past participle asked emphasizes the transitive nature of ask. Perhaps that makes it a tad "rougher".