keystore: Fix PEM certs handling am: 7ad2a87249 am: d1c5483a9a am: 5aea71565b

Original change: https://googleplex-android-review.googlesource.com/c/platform/external/wpa_supplicant_8/+/15433405

Change-Id: I6ebd01028f73df3c40882d6cf7552cd20196a10f