【报Bug】音频录音功能在首次打开APP进入该页面时不执行recorderManager1.onStart方法，然后后退再次进入时能进入。

示例代码：

<template>  
    <view>  
        <button @tap="playVoice">播放录音</button>  
        {{result}}  
    </view>  
</template>  
<script>  
    let options = {  
        duration: 60000,  
        sampleRate: 16000,  
        numberOfChannels: 1,  
        encodeBitRate: 48000,  
        format: 'mp3',  
        frameSize: 50  
    }  
    export default {  
        data() {  
            return {  
                result: false,  
                text: 'uni-app',  
                voicePath: '../../static/62497238-e924-401a-b1d7-e20c8f9ef8b9.wav'  
            }  
        },  
        mounted() {  
            this.playVoice();  
        },  
        methods: {  
            playVoice() {  
                this.recorderManager1 = uni.getRecorderManager();  
                this.innerAudioContext1 = uni.createInnerAudioContext();  

                this.innerAudioContext1.src = this.voicePath;  
                console.log('播放录音');  
                this.innerAudioContext1.play();  

                this.innerAudioContext1.onPlay(() => {  
                    console.log("play")  
                    console.log("play time:" + this.innerAudioContext1.duration)  
                })  

                this.innerAudioContext1.onEnded(() => {  
                    console.log("onEnded")  

                });  

                this.recorderManager1.start();  

                // 监听录音开始  
                this.recorderManager1.onStart(() => {  
                    console.log('recorder2 start')  
                    this.result = true;  

                })  

            }  
        }  
    }  
</script>  

<style>  

</style>  

操作步骤：

注:第一步复现步骤必须是打开APP第一次进入>>  
第一步产生的BUG：打开APP后点击“进入录音”按钮，无法进入到录音开始this.recorderManager1.onStart，打印日志如下>>  
17:40:06.419 App Show at App.vue:7  
17:40:09.253 App Launch at App.vue:4  
17:40:09.274 App Show at App.vue:7  
17:40:11.226 [Number] 1  at pages/index/index.vue:22  
17:40:11.246 播放录音 at pages/index/test.vue:34  
17:40:11.329 play at pages/index/test.vue:37  
17:40:11.359 play time:11.2 at pages/index/test.vue:38  
17:40:13.547 onEnded at pages/index/test.vue:41  

注：此时已经打开APP再次点击按钮  
第二步产生的BUG：点击左上角返回，然后再次点击“进入录音”按钮，再次进入test页面，此次能进入到录音开始this.recorderManager1.onStart，改变返回值this.Result=true，但是绑定显示{{result}}依然未变，打印日志如下>>  
17:41:39.961 [Number] 1  at pages/index/index.vue:22  
17:41:40.064 播放录音 at pages/index/test.vue:34  
17:41:40.664 play at pages/index/test.vue:37  
17:41:41.264 play time:11.2 at pages/index/test.vue:38  
17:41:42.385 onEnded at pages/index/test.vue:41  
17:41:42.406 recorder2 start at pages/index/test.vue:46  

预期结果：

期望每次点击“进入录音”按钮功能时都能正常进入以下方法体，并且能够改变绑定显示的值{{result}}  
this.recorderManager1.onStart(() => {  
        console.log('recorder2 start')  
        this.result = true;  
})  

获取的语音文件时长在华为荣耀10手机和MUMU模拟器中显示的时长为11.2秒，但文件真实的时长只有2秒，在OPPO RENO 3 PRO手机中测试能显示是正常的2秒。  
 this.innerAudioContext1.duration  

实际结果：

第一步结果未进入以下方法体  
this.recorderManager1.onStart(() => {  
        console.log('recorder2 start')  
        this.result = true;  
})  

第二步结果进入了以下方法体，但是未能改变绑定{{result}}的显示值  
this.recorderManager1.onStart(() => {  
        console.log('recorder2 start')  
        this.result = true;  
})