Update error text

Text was updated to be slightly more readable, but, wound up breaking
the tests. Reverting the word change.

Change-Id: I299245fc05f15ff6f7979c4c0365fe885b3c2e15
Fixes: 69056838
Test: cts-tradefed run commandAndExit cts-dev -m CtsAppSecurityHostTestCases -t android.appsecurity.cts.PkgInstallSignatureVerificationTest#testCorrectCertUsedFromPkcs7SignedDataCertsSet
Test: cts-tradefed run commandAndExit cts-dev -m CtsAppSecurityHostTestCases -t android.appsecurity.cts.PkgInstallSignatureVerificationTest#testV1SchemeSignatureCertNotReencoded
Test: cts-tradefed run commandAndExit cts-dev -m CtsAppSecurityHostTestCases -t android.appsecurity.cts.PkgInstallSignatureVerificationTest#testV2SchemeSignatureCertNotReencoded