Revert "Generate soong_config_module_type inline in the snapshot"

This reverts commit d29f8e0597.

Although I tested this well using unit tests they don't test 
everything and although I tested the unpacking of some snapshots I did
not test what happens when all the ART sdk/module_exports
snapshots are unpacked. I just did and the build broke.

The build broke because while the soong_config_module_type modules are
marked as being Nameless (and so according to the documentation do not
have to have unique names) it turns out that is not true.

There is at least one place in the build where the names of Nameless
modules are checked and as a result this breaks.

I could fix the build breakage reasonably easily but the problem is 
that I would have to apply that fix on all partners otherwise they
wouldn't be able to receive the next set of snapshots which is too 
high a cost.

So, I am reverting this and will limit the use of inline 
soong_config_module_type modules to optional modules.

Reason for revert: Breaks the build when snapshots are unpacked.

Bug: 233965247
Change-Id: I1faae863c48f1fbfd49d2545f242401bdd4f8f8a

build/mainline_modules_sdks_test.py

@@ -399,7 +399,8 @@ class TestSoongConfigBoilerplateInserter(unittest.TestCase):
         """Tests the transformations applied to a common mainline module.
 
         This uses ipsec as an example of a common mainline module. This checks
-        that the general Soong config module types and variables are used.
+        that the correct Soong config module types and variables are used and
+        that it imports the definitions from the correct location.
         """
         src = read_test_data("ipsec_Android.bp.input")
 
@@ -415,7 +416,7 @@ class TestSoongConfigBoilerplateInserter(unittest.TestCase):
 
         The ART mainline module uses a different Soong config setup to the
         common mainline modules. This checks that the ART specific Soong config
-        module types, and variables are used.
+        module types, variable and imports are used.
         """
         src = read_test_data("art_Android.bp.input")