[issues-1035] fix kotlion incrementalFilter createResource NPE

[gerenvip]

功能：修复 启用 doc 的场景下， RouteProcessor 基于 kotlion 增量编译Filter时 创建 docWriter 触发JavaNullPointerException

Issues[1035]： #1035

crash 原因：
https://github.com/JetBrains/kotlin/blob/master/plugins/kapt3/kapt3-base/src/org/jetbrains/kotlin/kapt3/base/incremental/incrementalProcessors.kt
override fun init(processingEnv: ProcessingEnvironment) {
if (!kind.canRunIncrementally) {
processor.init(processingEnv)
} else {
val originalFiler = processingEnv.filer
val incrementalFiler = IncrementalFiler(originalFiler)
val incProcEnvironment = IncrementalProcessingEnvironment(processingEnv, incrementalFiler)
processor.init(incProcEnvironment)
incrementalFiler.dependencyCollector = dependencyCollector.value
}
}

执行 processor.init(incProcEnvironment) 时 还没有给 dependencyCollector 赋值，RouteProcessor#init 时
mFiler.createResource 会调用 dependencyCollector 导致 空指针

解决方案：

1. 不启用 generateDoc
2. 延迟初始化 docWriter

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