Consistently trim string parameters

None of the string parameters can meaningfully have leading or
trailing whitespace, so trim them all for consistency.

Change-Id: I6a4cb55daa60c3e7a03f4e4e0f60678bf06a963b
diff --git a/mbedtls-release-ci-testing.yaml b/mbedtls-release-ci-testing.yaml
index 2a18123..515c61c 100644
--- a/mbedtls-release-ci-testing.yaml
+++ b/mbedtls-release-ci-testing.yaml
@@ -14,22 +14,22 @@
         default: ssh://git@github.com/Mbed-TLS/mbedtls.git
         description: Mbed TLS repo/fork
         name: MBED_TLS_REPO
-        trim: 'true'
+        trim: true
     - string:
         default: development
         description: Branch or commit to test
         name: MBED_TLS_BRANCH
-        trim: 'true'
+        trim: true
     - string:
         default: ssh://git@github.com:Mbed-TLS/mbedtls-framework.git
         description: Framework repo/fork to override the one specified in the Mbed TLS branch (only used if FRAMEWORK_BRANCH is also set)
         name: FRAMEWORK_REPO
-        trim: 'true'
+        trim: true
     - string:
         default: ''
         description: Framework branch/sha to override the sha specified in the Mbed TLS branch
         name: FRAMEWORK_BRANCH
-        trim: 'false'
+        trim: true
     - bool:
         default: false
         description: Run basic-build-test.sh (test coverage measurement)
@@ -54,7 +54,7 @@
         name: TEST_BRANCH
         description: Branch or tag in https://github.com/Mbed-TLS/mbedtls-test.git (forks are not supported)
         default: main
-        trim: 'false'
+        trim: true
     - string:
         name: TEST_PASS_EMAIL_ADDRESS
         description: E-mail addresses (delimited by ,) that a report should be sent to when the test run passes