Android Version differs from expected API level I have found a pretty old device Huawei Ascend Y210. This mobile officially has Android 2.3.3 (API level 10). I found an online custom lollipop ROM for the specific mobile. The device has CWM as custom recovery. The zip file (the rom file) was installed successfully. The environment feels like android Lollipop should look like. Going to the mobile's settings > About phone > Android version, the version is 5.0.1 as expected. Using the command adb shell getprop ro.build.version.release the result is 5.0.1 indeed. However, I tried running adb shell getprop ro.build.version.sdk the result is 10 which is the API level of the stock android of the phone (Android 2.3.3). Apps made from API level 23 will fail to install as the API level is getting recognized as 10. Changing the apps' Minimum API level to 10 using APK Editor Studio, allows the app to get installed but it crashes once I try to open it.

Is that a bug? I mean can I somewhere change the API level of the device? Or is the ROM a scam and the android is never really getting updated to 5.0.1 and the ROM just changes the graphic interface?  How is it even possible to trick the adb that the android version is 5.0.1 but keep the API level to 10?

P.S.: If someone has any ROM for Huawei Ascend Y210 with android 5.0.1 or higher handy, I would appreciate a download link.

Thanks in advance!
As Izzy mentioned the issue here was that the owner of the ROM had modified the ro.build.version.sdk in the build.prop without actually provide any feature of the API level 23. I am not sure if Fidz's answer is correct since I could not find any resource online that claims the same thing (correct me if I am wrong), Google's official site claims nothing about the API level, it just mentions some thing about the Android Compatibility regardless of the API level and the hardware. I could not find any ROM for the device since it's pretty old and almost every support for the Huawei and Honor phones on custom ROMs and rooting is dead after Huawei disabling the ability to unlock the bootloader.