Annotation processor uses class name as package name causing conflicts

**Glide Version**: 4.x

**Integration libraries**: N/A

**Device/Android Version**: N/A

**Issue details / Repro steps / Use case background**:

https://github.com/bumptech/glide/blob/eff228fcafc2a3e6077d15d0f2a995edf46f1f56/annotation/compiler/src/main/java/com/bumptech/glide/annotation/compiler/AppModuleProcessor.java#L84

See https://groups.google.com/forum/?utm_medium=email&utm_source=footer#!msg/glidelibrary/ZreirxaqMu0/QGhfJKJoBAAJ

Related: https://github.com/bumptech/glide/issues/2512

**Glide load line / `GlideModule` (if any) / list Adapter code (if any)**:
```java
package com.example;
class MyApp {
@GlideModule
static class MyModule {
}
}
```
will generate `com.example.MyApp.GlideApp;` where `MyApp` will be a package and this conflicts with the outer class from the app.