Impossible to use InfluxDB w/ systemctl on a Raspberry Pi 3B+

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__Steps to reproduce:__
Installation on Raspberry Pi, with a `pi` user and the usual `root` user.

1. Install `influxdb` with `apt`
2. `sudo systemctl enable influxdb`
3. `sudo systemctl start influxdb`

First error, from `journalctl -f -u influxdb` :
```
influxd[29953]: run: parse config: open /etc/influxdb/influxdb.conf: no such file or directory
```

4. Create the conf file with `influxd config > /etc/influxdb/influxdb.conf`
5. `sudo systemctl start influxdb`

Second error :
```
influxd[30111]: run: create server: mkdir all: mkdir /root/.influxdb: permission denied
```

6. Change the directory paths in `/etc/influxdb/influxdb.conf` to `/home/pi/.influxdb`
7. `sudo systemctl start influxdb`

Third error :
```
influxd[30242]: run: create server: mkdir all: mkdir /home/pi/.influxdb: permission denied
```

__Expected behavior:__
Working InfluxDB service

__Actual behavior:__
InfluxDB service doesn't work.

__Environment info:__

* System info: Raspberry Pi 3B+, Raspbian GNU/Linux 10 (buster), `Linux 4.19.97-v7+ armv7l`
* InfluxDB version: InfluxDB v1.8.0 (git: 1.8 781490de48220d7695a05c29e5a36f550a4568f5)
* Other relevant environment details: Container runtime, disk info, etc

__Config:__
Specified above.

__Additional info__
Running `influxd` works.

Start with the systemd service launched by `sudo systemctl start influxdb` and the configuration at `/etc/influxdb/influxdb.conf`. Reproduce the failure on the stated Raspberry Pi/Raspbian environment and inspect `journalctl -f -u influxdb`, focusing on the missing configuration and permission errors. Done means the packaged service starts successfully without requiring manual path changes.

Written by the indexing model from the issue text.