fallback to manually consume space if posix_fallocate isn't supported…

… at runtime

CHANGELOG.md

@@ -6,7 +6,7 @@
 
 ### Fixed
 * <How do the end-user experience this issue? what was the impact?> ([#????](https://github.com/realm/realm-core/issues/????), since v?.?.?)
-* None.
+* Handle `EOPNOTSUPP` when using `posix_fallocate()` and fallback to manually consume space. This should enable android users to open a Realm on restrictive filesystems. ([realm-js #6349](https://github.com/realm/realm-js/issues/6349), more prevalent since v13.23.3 with the change to `REALM_HAVE_POSIX_FALLOCATE` but it was also an issue in some platforms before this)
 
 ### Breaking changes
 * `App::get_uncached_app(...)` and `App::get_shared_app(...)` have been replaced by `App::get_app(App::CacheMode, ...)`. The App constructor is now enforced to be unusable, use `App::get_app()` instead. ([#7237](https://github.com/realm/realm-core/issues/7237))

src/realm/util/file.cpp

@@ -1010,7 +1010,7 @@ bool File::prealloc_if_supported(SizeType offset, size_t size)
         return true;
     }
 
-    if (status == EINVAL || status == EPERM) {
+    if (status == EINVAL || status == EPERM || status == EOPNOTSUPP) {
         return false; // Retry with non-atomic version
     }