I've just Googled and the power supply voltage range is 2V to 3.6V.
https://www.digikey.co.uk/product-detail/en/STM32F100C4T6B/497-10501-ND/2259219?WT.z_slp_buy=stm_stm32f1Unless an external reference is used, presumably the maximum ADC input voltage is equal to the power supply. I agree about using a slightly lower value resistor so there's some leeway for component tolerances. 160R will give a voltage range of 0.64V to 3.2V.
Yes some protection of the ADC pin is a good idea, but it doesn't have to be hugely complicated. A resistor and capacitor will probably do, for most applications.
A PTC resistor (polyfuse) will provide little protection against the sensor being short circuited, unless the resistor is sufficiently overrated, as PTC resistors are slow. An active current limiting circuit might be more effective.
EDIT:
See attached schematics. As the resistance of the sensor is swept, the current varies in accordance with Ohm's law, up to about 22mA, then the voltage across the sensor is reduced and even if its resistance falls to 10 Ohms, the current drops to just under 23mA. The ADC voltage is of course directly proportional to the current and is limited at just over 3.6V, which will pose no problem, as R3 will limit the current into the ADC to a very low level.
V2 must be able to sink all the current flowing through R2, which will be just under 2.8mA, assuming the worst case supply voltage of 28V. A 1k2 resistor, a TL431 circuit, or zener across the 3.3V supply could be used, if the supply voltage rises.
